Why is Renewable Energy important today?

Energy Price Stability

In the last three years, we have seen large fluctuations in the cost of natural gas, oil and electricity due to global economics, market deregulation and political events in some parts of the world. Renewable energy is not subject to sharp price changes because it comes from sources such as sunshine, flowing water, wind and biological waste, all of which are free. This gives people greater certainty about the cost of energy, which is good for society and the economy. By comparison, fossil fuels are limited in their supply and their price will increase as they become scarcer.

Clean Air

Air pollution is a major problem in many cities in Nepal and around the world. The biggest cause of air pollution in cities is the burning of fossil fuels, including fuels used for transportation. The great advantage of using renewable energy in place of fossil fuels is that renewable energy adds very few pollutants to the environment. Renewable energy is considered “clean” and “green”.

Protecting Global Climates

When fossil fuels are burned, they release carbon dioxide. This gas acts like an invisible blanket, trapping more of the sun’s energy in the atmosphere, causing the Earth to warm up little by little. Carbon dioxide is building up in the atmosphere as more and more fossil fuels are used in homes, factories and automobiles. If this continues, most scientists think our planet is likely to become significantly warmer, which could cause many serious problems around the world. These problems could include melting of arctic ice, increased forest fire, rising sea levels, loss of animal habitat, damage of coral reefs, the spreading of tropical diseases, expanding deserts and more frequent and severe storms.

Protecting Landscapes and Watersheds

Some energy projects, particularly big coalmines. Hydro dams and oil & gas activities can have a large impact on lands and watersheds. Damage or loss of natural lands and watersheds is likely to affect humans and animals. For example, wilderness areas could be lost for when energy resources are extracted. Hydro dams can flood large areas, while the facilities associated with oil and gas and oil sands development can affect forests and disrupt animal movements and migrations. On the other hand, Solar energy can provide a continuous supply of energy, which is integrated directly into buildings so that it has very little impact on land use. Run-of-Rover hydro plants can be designed to allow for free flow of existing streams.

Unlimited Supplies

Renewable energy supplies will never run out. While the supplies of coal, oil and natural gas are limited, sunshine, wind, biomass and water power are considered almost limitless resources. Our large, untapped supplies of wind, sun, water and biomass can power our society indefinitely.

Jobs and Economy

Renewable energy can be developed in such a way that every household or neighbourhood could have its own renewable power generating equipment. This would create many new jobs for people involved in setting up and maintaining this energy supply and in manufacturing the equipment. It is also more efficient to produce renewable energy in small amounts right where it is needed. The energy loss and equipment needed to transmit power over long distances can also be minimized in this way.

Read More

Solar Energy

Solar energy is the radiant light and heat from the sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources account for most of the available renewable energy on earth.

However, only a minuscule fraction of the available solar energy can be used to:
Generate Electricity
Heating and Cooling
Cooking
Water Desalination


Solar Radiation at the Earth's Surface

While the solar radiation incident on the earth's atmosphere is relatively constant, the radiation at the earth's surface varies widely due to:
Atmospheric effects, including absorption and scattering; Local variations in the atmosphere, such as water vapour, clouds, and pollution; Latitude of the location; Season of the year and the time of day.

The above effects have several impacts on the solar radiation received at the earth's surface. These changes include variations in the overall power received, the spectral content of the light and the angle from which light is incident on a surface. In addition, a key change is that the variability of the solar radiation at a particular location increases dramatically. The variability is due to both local effects such as clouds and seasonal variations, as well as other effects such as the length of the day at a particular latitude. Desert regions tend to have lower variations due to local atmospheric phenomena such as clouds. Equatorial regions have low variability between seasons.


Solar Technologies and Techniques

Solar energy technologies refer primarily to the use of solar radiation for practical ends. All other renewable energies other than geothermal derive their energy from energy received from the sun.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of photovoltaic modules (also called photovoltaic panels) and solar thermal collectors (with electrical or mechanical equipment) to convert sunlight into useful outputs. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.

Solar Thermal Technologies
 

Solar thermal technologies are harnessing solar energy for thermal energy (heat). Solar thermal technologies comprise flat collectors for low- and medium temperatures and high temperature collectors concentrating sunlight using mirrors and lenses.

Solar Electric Technologies

Sunlight can be directly converted into electricity using photovoltaics (PV) and various experimental technologies.

Read More

Solar Thermal Technologies

Solar thermal technologies involve harnessing solar energy for thermal energy (heat). Solar thermal technologies comprise flat or parabollic collectors (low and medium temperatures and high temperature collectors) concentrating sunlight mainly using mirrors and lenses. Solar heating is the utilisation of solar energy to provide process heat, especially in crop drying, water heating, cooking or space heating and cooling. Advanced designs are also used to generate electricity.

Solar Water Heaters (SWH)

The Technology

Solar water heating (SWH) systems are typically composed of:

• Solar thermal collectors(flat plate or evacuated tube)
• Storage tank
• Circulation loop.

SWH can be either active system or pasive systems:

• Active systems which use pumps to circulate water or a heat transfer fluid. There are the two types of active solar water-heating systems:

1. Direct-circulation systems use pumps to circulate pressurized potable water directly through the collectors. These systems are appropriate in areas that do not freeze for long periods and do not have hard or acidic water.
2. Indirect-circulation systems pump heat-transfer fluids through collectors. Heat exchangers transfer the heat from the fluid to the potable water. Some indirect systems have "overheat protection," which is a means to protect the collector and the glycol fluid from becoming super-heated when the load is low and the intensity of incoming solar radiation is high.

• Passive systems transfer and circulate heat naturally. Passive solar water heaters rely on gravity and the tendency for water to naturally circulate as it is heated. Because they contain no electrical components, passive systems are generally more reliable, easier to maintain, and possibly have a longer work life than active systems. The two common types of passive systems are:

1. Integral-collector storage systems or batch systems consist of a tank that is directly heated by sunlight. These are the oldest and simplest solar water heater designs. They are good for households with significant daytime and evening hot-water needs; but they do not work well in households with predominantly morning draws because they lose most of the collected energy overnight. These solar collectors are suited for areas where temperatures rarely go below freezing.
2. Thermosyphon systems are an economical and reliable choice. These systems rely on the natural convection of warm water rising to circulate water through the collectors and to a storage tank located above the collector. As water in the solar collector heats, it becomes lighter and rises naturally into the tank above. Meanwhile, the cooler water flows down the pipes to the bottom of the collector, enhancing the circulation. Indirect Thermosyphon systems use a glycol fluid in the collector loop as a heating medium.

To design, size and select a solar water heating system, the following data is required: daily hot water requirement (litres/day), average insolation (kWh/m2 day), water quality and storage requirements.

Flat Plate Collector

A flat plate is the most common type of solar thermal collector, and is usually used as a solar hot water panel to generate hot water. A weatherproofed, insulated box containing a black metal absorber sheet with built in pipes is placed in the path of sunlight. Solar energy heats up water in the pipes causing it to circulate through the system by natural convection. The water is usually passed to a storage tank located above the collector.
There are many flat-plate collector designs but generally all consist of:

1. a flat-plate absorber, which intercepts and absorbs the solar energy,
2. a transparent cover that allows solar energy to pass through but reduces heat loss from the absorber,
3. a heat-transport fluid (air, antifreeze or water) flowing through tubes to remove heat from the absorber and
4. a heat insulating backing.

One flat plate collector is designed to be evacuated, to prevent heat loss. The absorber may be made from one of a wide range of materials, including copper, stainless steel, galvanised steel, aluminium and plastics. When choosing an absorber material, it is important to ensure that it is compatible, from the point of view of corrosion, with the other components in the system and with the heat transfer fluid used. The absorber must also be able to withstand the highest temperature that it might reach on a sunny day when no fluid is flowing in the collector (known as the stagnation temperature).

The fluid passageways of the absorber may consist of tubes bonded to an absorbing plate, or may form an integral part of the absorber. Experience has shown that simple mechanical clamping of tubes to an absorber plate is likely to result in an absorber with a poor efficiency. A good thermal bond, such as a braze, weld or high temperature solder is required for tube and plate designs, in order to ensure good heat transfer from the absorbing surface into the fluid.

Matt black paints are commonly used for absorber surfaces because they are relatively cheap, simple to apply and may be easily repaired. Paints, however, have the disadvantage that they are usually strong emitters of thermal radiation (infrared), and at high temperature this results in significant heat losses from the front of the collector. Heat losses from the collector can be substantially reduced by the use of absorber coatings known as 'selective surfaces'. These surfaces may be applied by electroplating or by dipping a metal absorber in appropriate chemicals to produce a thin semi-conducting film over the surface. The thin film will be transparent to solar radiation but at the same time appear opaque to thermal radiation. However, these surfaces cannot be produced or applied easily.

Flat-plate collectors usually have a transparent cover made of glass or plastic. The cover is required to reduce heat losses from the front of the collector and to protect the absorber and the insulation from the weather. Most covers behave like a greenhouse. They permit solar radiation to pass into the collector, but they absorb the thermal radiation emitted by the hot absorber.

At night it is possible for the collector to lose heat by radiation and the circulation will be in the opposite direction, so the water will cool. This can be overcome by use of a suitable non-return valve. However, there is a danger with solar collectors when used under clear night conditions (e.g. in arid and semi arid regions) that they can actually freeze even when the ambient temperature is above freezing point. In such conditions it may be necessary to have a primary circuit through the collector filled with antifreeze and a separate indirect hot water cylinder where the water from the collector passes through a copper coil to heat the main water supply. This problem will only apply in certain desert regions in the cold season or at high altitudes in the tropics and sub-tropics.

Evacuated Tube Collector

Applications and Efficiency

SWHs are employed in residential, commercial, industrial and public buildings and in industrial processes (drying, pre-heating boiler feed water, cleaning, etc. - see examples for potential on solar thermal applications in industries in India) for the provision of hot water, heat and cooling.

The current commercial market for SWH in the region is predominantly households (high income), hospitals, commercial establishments and tourist facilities.

State of the art solar water heaters incorporate features such as selective surface absorbers, anti-reflective glazing, well-designed collector arrays, efficient storage systems achieving operation efficiencies of the order of 35 to 40%.
A 300-liter system typically suited for family of 4-6 persons will displace up to 1000 kWh of electricity annually.

Capability and Limitations

• Water quality - Solar water heaters require clean, non-hard water for long term operation. Hard or dirty water leads to blockage and corrosion of pipes and storage tanks. Closed circuit systems are recommended where water is hard.
• Installation, Commissioning and Maintenance - Improper installation and commissioning and maintenance of SWHs are the leading causes of system failures.
• High cost of SWH is a major limitation in their uptake. Typical prices for small units range between US$ 1,500 (180 litres) to US$ 2,500 (300 litres).

Costs

Low temperature flat-plate solar collectors typically cost 21 US $ per square metre (0,0021 US $ /cm²). Medium to high temperature collectors generally cost around 200 US $ per square metre. Flat plate collectors are sized at approximately 0,1 square metre (929 cm²) per gallon (3,79 l ) of daily hot water use or 245 cm² per l of hot water. A complete system installed costs around 14 US $/l or 2000 US $ per 150 l.

Maintenance

Solar thermal systems are relatively maintenance free and involve on an occasional basis the checking of the piping for leaks and the cleaning of the collectors. In some regions it may also be necessary to inspect the transfer fluid for freeze protection and to remove the build up of lime scale that chokes the collector and tank recirculating pipes over a period of time.

Read More

Solar Electric Technologies

Solar energy can be converted directly or indirectly into electricity by the use of the solar electric technologies:

DIRECT: With the use of photovoltaic modules.

INDIRECT: With concentrating solar power.

Photovoltaics (PV) system

Photovoltaics (PV) is the field of technology and research related to the application of solar cells for energy production by converting the solar radiation (sunlight, including sun ultra violet radiation) directly into electricity using the photovoltaic effect.

The PV systems can be grid conected or off grid. Off grid system or stand alone systems are the so called solar home systems (SHS).

In the case of concentrating solar power the solar radiation is concentrated into a small area. This heats up a flud that is used to power a heat engine conected to a generator to produce electricity.

Solar Bottle Bulbs

Solar bottle bulbs were first developed in Brazil and since then has been adopted in different parts of the world.

Read more here....

Read More

Photovoltaic (PV)

Photovoltaics (PV) is the field of technology and research related to the application of solar cells for energy production by converting sun energy (sunlight, including sun ultra violet radiation) directly into electricity by the photovoltaic effect. The latter refers to the process of converting light (photons) to electricity (voltage). Solar cells are photovoltaic devices that use semi-conducting materials to convert sunlight directly into electricity. When sunlight is absorbed by these materials, it causes electrons to flow through the material generating electric currents. Solar cells produce direct current (DC) electricity. There are two broad categories of solar cells; thin film and crystalline.

The key components of a photovoltaic power system are the photovoltaic cells (also called solar cells) interconnected and encapsulated to form a photovoltaic module (the commercial product), the mounting structure for the module or array (several modules mounted and interconnected together to produce a desired voltage and current (power capacity)), the inverter (essential for grid-connected systems and required for many off-grid systems), the storage battery and the charge controller (for off-grid systems only). Solar cells are typically combined into modules that hold up to 40 cells to generate substantial voltages (typically 12 V or 24V) and currents that can be used to power various devices. The power output of a module is measured under standardized test conditions in Watt Peak (Wp).

Performance of PV modules depends on the amount of solar irradiation received which varies by location and season. For this reason, systems normally need to be carefully designed. A typical commercial solar cell has an efficiency of 15%. The first solar cells, built in the 1950s, had efficiencies of less than 4%.

Applications and Efficiency
PV technology can be employed in a variety of applications: Typical applications of PV technology include remote telecommunications, cathodic protection of pipelines, PV home systems, vaccine refrigeration, water pumping, grid connected or building integrated systems, miniature electronic devices and toys:

Off-grid domestic PV systems like solar home systems:
Provide electricity to households and villages that are not connected to the utility electricity network (also referred to as the grid) Provide electricity for lighting, phone charging, refrigeration and other low power loads. Are often the most appropriate technology to meet the energy demands of off-grid communities

Off-grid non-domestic PV installations:
Are used in locations where small amounts of electricity have a high value Were the first commercial application for terrestrial PV systems Provide power for a wide range of applications, such as telecommunication, water pumping, vaccine refrigeration and navigational aids Make PV commercially cost competitive with other small generating sources

Grid-connected distributed PV systems:
Provide power to grid-connected customers or directly to the electricity network (specifically where that part of the electricity network is configured to supply power to a number of customers rather than to provide a bulk transport function). May be on or integrated into the customer's premises, often on the demand side of the electricity meter, on public and commercial buildings, or elsewhere in the built environment

Grid-connected centralized PV systems:
Perform the functions of centralized power stations Supply power that is not associated with a particular electricity customer Primarily supply bulk power, rather existing on the electricity network to perform specific functions.

To design a system for PV application the following information is required: daily energy requirement, voltage and current draw of appliances, average insolation (kWh/m2 day), the yearly variation in insolation levels for the specific area and the equipment type, availability and costs to enable appropriate selection.

Capability and Limitations
The number and type of appliances that can be used with SHS is limited. Lights, TVs, sound systems and low-wattage DC appliances are appropriate.
Costs of well designed, installed and maintained systems are relatively high on a cash basis although the life cycle cost of PV is often less than comparison technologies. 

 
Sales, installation and support infrastructure for systems is largely underdeveloped leading to higher delivery and maintenance cost. 

 
Experiences show that security is essential for most PV installations. In remote unguarded locations, there is risk of the modules and other system components being stolen or vandalized.

Read More

Solar Home Systems

Solar home system (SHS) are stand-alone photovoltaic systems that offer a cost-effective mode of supplying amenity power for lighting and appliances to remote off-grid households. In rural areas, that are not connected to the grid, SHS can be used to meet a household's energy demand fulfilling basic electric needs. Globally SHS provide power to hundreds of thousands of households in remote locations where electrification by the grid is not feasible. SHS usually operate at a rated voltage of 12 V direct current (DC) and provide power for low power DC appliances such as lights, radios and small TVs for about three to five hours a day. Furthermore they use appliances such as cables, switches, mounts, and structural parts and power conditioners / inverters, which change 12/ 24 V power to 240VAC power for larger appliances. SHS are best used with efficient appliances so as to limit the size of the array.

A SHS typically includes one or more PV modules consisting of solar cells, a charge controller which distributes power and protects the batteries and appliances from damage and at least one battery to store energy for use when the sun is not shining.

They contribute to the improvement of the standard of living by: reducing indoor air pollution and therefore improving health as they replace kerosene lamps, providing lighting for home study, giving the possibility of working at night and facilitating the access to information and communication (radio, TV, mobile phone charging).

Furthermore, SHS avoid greenhouse gas emissions by reducing the use of conventional energy ressources like kerosene, gas or dry cell batteries or replacing diesel generators for electricity generation. Further impacts of renewable energies, such as SHS, can be found in the Report on Impacts.

Stand-alone photovoltaic systems can also be used to provide electricity for health stations to operate lamps during night and a refrigerator for vaccines and medicines to better serve the community.



Technical Standards for Solar Home Systems (SHS)

To assure the quality of a photovoltaic power system and its correct functioning and guarantee costumers' satisfaction, it is important that the components of the system and the system as a whole meet certain requirements.

The GIZ prepared a publication which gives an overview of different standardisation activities and existing standards that are relevant for solar home systems (SHS) and rural health power supply systems (RHS): Technical Standards for SHS.

Solar Panel on Roof

Planning, Installation and Maintenance of Solar Home Systems (SHS)

Before installing a photovoltaic (PV) SHS, its size has to be calculated according to different assumptions, such as measurement of solar radiation, solar insolation and power demand. Regarding the installation process, Solar Home Systems have to be installed by a trained technician who knows how to handle its different parts. Thus, aspects of mainentance and a solar technical training manual is presented: Planning, Installation and Maintenance of SHS.

Costs

Typical systems costs in the Eastern Africa region range between US$ 170 for a 12 Wp system and up to US$ 2,000 for a 150 Wp system. For developed countries the average cost per installed watt for a residential sized system is about US$ 6.50 to US$ 7.50, including panels, inverters, mounts, and electrical items. In Eastern Africa the cost is 2-3 times higher.

Read More

Solar Hybrid Systems

Solar hybrid systems generate power using a solar power generator like photovoltaic (PV) modules and additional renewable energy sources (e.g.,) and/or a supplementary generator.

In remote rural areas, that are not connected to the national electricity grid, village mini grids consisting of PV hybrid systems might be less costly than grid extension. They can replace batteries and fuel electricity generators and reach more people than single solar home systems (SHS).

Function

During the day, when the Sun is shining, the photovoltaic modules generate electricity that directly powers appliances or can be stored in a battery bank. At night or during days without sunshine the stored energy can be used. The supplementary generator makes the system reliable, offering the possibility of producing power at any time. Therefore, solar hybrid systems can offer alternating current (AC) power for 24 hours a day. 

The HOMER tool, developed by the U.S. National Renewable Energy Laboratory (NREL), is useful for designing and modeling hybrid systems. The HOMER tool automatically retrieves solar insolation information from NASA.

Read More

Uses of Solar Energy

Various possibilities of using solar energy exist. Here you find a few applications and experiences with them in projects.


Uses of Solar Energy:

Solar Street Lights

Electric street lights consume high amounts of energy, which makes solar street lights attractive. They can be used at streets, highways, parks and villages. An important impact is increased security. In this section, tips, tricks as well as common sources of failures are described.

Solar Battery Charging Stations

Battery charging stations are usually not the first choice for Rural electrification, but they can be viable in remote areas were no other alternatives exist and the income of the population is too low to invest in other solutions as for example solar home systems. Costs, models, leassons learned and exapmles with solar battery charging stations can be read up in this section.

PV for Health Centers

An unreliable energy source adds to the daily challenges health facilities in rural areas face on a daily basis: If the cold chain is inoperable when supplies arrive, vaccines, blood, and other medicines may go to waste. If a clinic is without lights, patients arriving at night must wait until morning to receive care. Selecting an appropriate source of reliable and sustainable energy as well as introducing measures for efficient energy consumption can help mitigate some of the challenges inherent in operating a health facility in the developing world. This article will provide an overview on options for the improvement of the energy situation in rural health facilities and experience of projects in Ethiopia and Uganda.

Solar Pumping

There are two distinct fields of application for PV pumping systems: drinking water supply and irrigation. Experience from past projects has proven PV pumping systems to be technically mature and suitable for utilization in rural areas of developing countries. The systems in use have very low failure rates and are therefore highly reliable. Economics of PV pumping systems for irrigation is dependent on numerous factors, which are described in the article.

Solar Drying

Preservation of agricultural produce is an important challenge in developing countries in order to protect food from getting spoiled. But traditional sun drying methods often yield poor quality. Solar drying facilities combine traditional and industrial methods, meaning low investment costs and high product quality. Experience with Solar drying in Marocco is described in this article.

Cooking with Sun

Solar cookers have repeatedly been seen as a solution to the firewood problem. “Cooking with the sun” also allows the use of a free, effectively inexhaustible source of energy, relieves the workload on women, and reduces the harmful effects on health arising from cooking. Moreover, fewer trees are chopped down, thus stopping deforestation and the advance of desertification, while at the same time guarding against global warming. Roughly half of the million or so solar cookers in the world are used in China. This article gives an overview of types of solar cookers, disseminantion strategies and basic rules of use and diffusion.

Read More

Productive Use of Solar PV

Precise information about the installed capacity, or the number of renewable energy systems, used for productive uses in rural areas of less industrialized nations is not readily available; furthermore, published data regarding these figures are scarce. This lack of precise information is particularly notorious in relation to off-farm productive activities (e.g. cottage activities and commercial services). Most of the existing information is anecdotal in nature and provides only a glimpse of the current and potential renewable energy applications.

A FAO study from 2000 provides a good qualitative overview on potential productive uses and system set-ups of PV in different countries. Even though pointing out that electric lighting is by far the most common application of PV systems, the study provides a large amount of other income-generating applications in the areas of agriculture, cottage industries, and commercial businesses.

Agricultural Applications

In the area of agriculture solar PV is found to be useful for applications such as water pumping for (drip) irrigation and cattle drinking, aeration for aquacultures, refrigeration of agricultural products, electric fencing, poultry lighting (cp. Lighting Africa study), and pest control. The main impacts of solar electricity on agricultural activities are described as increased productivity (including higher yields, lower losses and faster production) and improved natural resource management.

The relevance of small PV systems for agricultural production is, however, limited to the provision of power for activities that require little power input. PV systems are not an option for energy intensive activities such as in rice mills and other agricultural processing.

Applications in Cottage Production and Commercial Industries
 

For cottage industries and commercial businesses, the most common reported examples of productive use are related to the prolonged working hours due to lighting. Lighting is reported to improve also the quality of the productive activity and to attract more customers, according to the nature of the business. To less extend PV systems are also used for providing power for music, TV and simple devices for these businesses as well as the powering of small monitoring devices and tools in electronic repair shops which can improve the quality of repair and the productivity of the workshop with very limited power demand. A GIZ project in Mongolia reported the use of an inverter for a milk centrifuge. Other applications include the sale of electricity or related services. Examples are solar battery and phone charging stations, rural telephone and internet services, as well as recreational service businesses such as small village cinemas and dancing halls. Positive impacts on cottage industries and commercial businesses include longer working and opening hours, higher productivity, higher attractiveness for customers, more employment, and the creation of new productive activities.

Restrictions of Solar PV for Productive Use
While solar PV seems appropriate for household lighting and applications that use small amounts of electricity, it may not be suitable for promoting productive applications on a largescale (e.g. machines for industrial manufacturing processes), largely because of the high costs of delivered electricity involved.
Still, the small-scale productive application of small loads from solar PV systems seem to be potential “carriers of rural socio economic development”.

In low power examples of PUE like cellphone charging or barber shops have a big potential.

Read More

Recycling of Solar Products

Introduction of solar products to local markets has to provide approaches for recycling, especially concerning mass production. Currently are only few options to handle used solar products. Since solar products consist mainly of some electronics and the battery, the latter is the first component which has to be replaced after a few years. No matter which material the battery contains, none of these should be placed in the environment. This draws the attention to two important aspects: consumer awareness and recycling of material.

As studies already proven, users mainly do not worry about environmental impacts. Thus, due to living circumstances exist only little awareness of environmental protection or climate change. Additionally, if people are not used to the usage of batteries, they are not informed about possible hazardous consequences. Therefore, it is important to pay attention to the topic of creating awareness among people already during the introduction phase.

Furthermore, waste disposal for batteries and recycling facilities should be provided within the countries. Few recycling facilities already exist, but there remain a lot of difficulties, which have to be faced, such as untrained employees, unknown factories, inappropriate recycling measures (concerning recycling quality and worker's health).

• Recycling of PV batteries

This article informs about the measures of recycling concering PV batteries, including technical steps, metallurgical aspects and environmental considerations.

• Recycling of PicoPV Systems

In this article specific considerations of recycling of PicoPV systems and already existing facilities are discussed.

Read More

Electricity Bill Savings with Solar Energy

Money saved on electricity through smaller or eliminated electricity bills should be factored into your cost of solar panels calculation. Have a look at your last few electricity bills and calculate your expected energy reduction – factor the $30, $50, or $100 expected monthly saving into your solar cost analysis.

Freedom from the fluctuations of electricity prices and from the international politics of fossil fuels is an enormous future cost-benefit of solar energy.  As fossil-fuel energy prices continue to rise, solar power users will remain unaffected.

Carbon emission taxes are another factor affecting the long term cost of solar power. As we struggle with the burgeoning climate change crisis, countries are imposing their own per kg carbon taxes and emissions trading schemes to curb pollution. These taxes will increasingly make fossil fuel generated electricity more expensive, thus make the comparative cost of solar cheaper.

Read More

Disadvantages of Solar Energy

Solar doesn’t work at night

The biggest disadvantage of solar energy is that it’s not constant. To produce solar electricity there must be sunlight. So energy must be stored or sourced elsewhere at night.

Beyond daily fluctuations, solar production decreases over winter months when there are less sunlight hours and sun radiation is less intense.

Solar Inefficiency

A very common criticism is that solar energy production is relatively inefficient.

Currently, widespread solar panel efficiency – how much of the sun’s energy a solar panel can convert into electrical energy – is at around 22%. This means that a fairly vast amount of surface area is required to produce adequate electricity.

However, efficiency has developed dramatically over the last five years, and solar panel efficiency should continue to rise steadily over the next five years.

For the moment though, low efficiency is a relevant disadvantage of solar.

Solar inefficiency is an interesting argument, as efficiency is relative. One could ask “inefficient compared to what?” And “What determines efficiency?” Solar panels currently only have a radiation efficiency of up to 22%, however they don’t create the carbon by-product that coal produces and doesn’t require constant extraction, refinement, and transportation – all of which surely carry weight on efficiency scales.

Storing Solar

Solar electricity storage technology has not reached its potential yet.

While there are many solar drip feed batteries available, these are currently costly and bulky, and more appropriate to small scale home solar panels than large solar farms.

Solar panels are bulky

Solar panels are bulky. This is particularly true of the higher-efficiency, traditional silicon crystalline wafer solar modules. These are the large solar panels that are covered in glass.

New technology thin-film solar modules are much less bulky, and have recently been developed as applications such as solar roof tiles and “amorphous” flexible solar modules. The downfall is that thin-film is currently less efficient than crystalline wafer solar.

One of the biggest disadvantages of solar energy – COST

The main hindrance to solar energy going widespread is the cost of installing solar panels. Capital costs for installing a home solar system or building a solar farm are high.

Particularly obstructive is the fact that installing solar panels has large upfront costs – after which the energy trickles in for free.

Imagine having to pay upfront today for your next 30 years worth of power.

That’s an incredibly disadvantageous feature of solar energy production, particularly during a time of recession.

Currently a mega watt hour of solar energy costs well over double a mega watt hour of conventional electricity (exact costs vary dramatically depending on location).

All is not lost though – nuclear is a good example (economically) of energy production that was initially incredibly expensive, but became more feasible when appropriate energy subsidies were put in place.

Read More

Advantages of Solar Energy

No green house gases

The first and foremost advantage of solar energy is that, beyond panel production, it does not emit any green house gases.

Solar energy is produced by conducting the sun’s radiation – a process void of any smoke, gas, or other chemical by-product.

This is the main driving force behind all green energy technology, as nations attempt to meet climate change obligations in curbing emissions.

Italy’s Montalto di Castro solar park is a good example of solar’s contribution to curbing emissions. It avoids 20,000 tonnes per year of carbon emissions compared to fossil fuel energy production.

Ongoing Free Energy

Another advantage of using solar energy is that beyond initial installation and maintenance, solar energy is free.

Solar doesn’t require expensive and ongoing raw materials like oil or coal, and requires significantly lower operational labor than conventional power production. Raw materials don’t have to be constantly extracted, refined, and transported to the power plant.

Life expectancy ranges between manufacturers, but many panels produced today carry a 25-30 year warranty – with a life expectancy of up to 40 years.

Decentralization of power

Solar energy offers decentralization in most (sunny) locations, meaning self-reliant societies.

Oil, coal, and gas used to produce conventional electricity is often transported cross-country or internationally. This transportation has a myriad of additional costs, including monetary costs, pollution costs of transport, and roading wear and tear costs, all of which is avoided with solar.

Of course, decentralization has its limits as some locations get more sunlight than others.

Going off the grid with solar

Solar energy can be produced on or off the grid.

On grid means a house remains connected to the state electricity grid. Off grid has no connection to the electricity grid, so the house, business or whatever being powered is relying solely on solar or solar-hybrid.

The ability to produce electricity off the grid is a major advantage of solar energy for people who live in isolated and rural areas. Power prices and the cost of installing power lines are often exorbitantly high in these places and many have frequent power-cuts.

Many city-dwellers are also choosing to go off the grid with their alternate energy as part of a self-reliant lifestyle.

Solar jobs

A particularly relevant and advantageous feature of solar energy production is that it creates jobs.

The EIAA states that Europe’s solar industry has created 100,000 jobs so far.

Solar jobs come in many forms, from manufacturing, installing, monitoring and maintaining solar panels, to research and design, development, cultural integration, and policy jobs.

The book Natural Capitalism offers a good perspective on the employment potential of green design and a prudent approach to using resources.

The book proposes that while green technology and associated employment can be expensive, much greater money can be saved when combined with proven “whole-system” efficiency strategies (e.g passive lighting and airflow).

With solar energy currently contributing only an estimated 4% of the world’s electricity, and an economic-model where raw materials don’t have to be indefinitely purchased and transported, it’s reasonable so assume solar jobs are sustainable if the solar industry can survive the recession.

Solar’s avoidance of politics and price volatility

One of the biggest advantages of solar energy is the ability to avoid the politics and price volatility that is increasingly characterizing fossil fuel markets.

The sun is an unlimited commodity that can be sourced from many locations, meaning solar is less vulnerable to the price manipulations and politics that have more than doubled the price of many fossil fuels in the past decade.

While the price of fossil fuels have increased, the per watt price of solar energy production has more than halved in the past decade – and is set to become even cheaper in the near future as better technology and economies of scale take effect.

Furthermore, the ever-abundant nature of the sun’s energy would hint at a democratic and competitive energy market – where wars aren’t fought over oil fields and high-demand raw materials aren’t controlled by monopolies.

Of course, a new form of politics has emerged with regard to government incentives and the adoption of solar, however these politics are arguably minor compared to the fossil fuel status quo.

Saving eco-systems and livelihoods

Because solar doesn’t rely on constantly mining raw materials, it doesn’t result in the destruction of forests and eco-systems that occurs with many fossil fuel operations.

Destruction can come in many forms, from destruction through accepted extraction methods, to more irresponsible practices in vulnerable areas, to accidents.

Major examples include Canada’s tar sands mining which involves the systematic destruction of the Boreal Forest (which accounts for 25% of the world’s intact forest land), and creates large toxic by-product ponds .

The Niger Delta is an example where excessive and irresponsible oil extraction practices have poisoned fishing deltas previously used by villagers as the main source of food and employment, creating extremely desperate poverty and essentially decimating villages.

A more widely known, but arguably lower human-cost incident is the 2010 BP oil spill in the Gulf of Mexico. It killed 11 people and spilled 780 thousand cubic meters of crude oil into the sea.

An interesting glance at the situation caused by destructive fossil fuel company practices in the Niger Delta. Sweet Crude is a good documentary if you want to learn more.

The best is yet to come

Solar technology is currently improving in leaps and bounds. Across the world, and particularly in Europe, savvy clean technology researchers are making enormous developments in solar technology.

What was expensive, bulky, and inefficient yesterday, is becoming cheaper, more accessible, and vastly more efficient each week.

Read More