The use of electricity through various appliances has evolved the standard of living for people to a completely new level. The thought of staying devoid of electricity for more than a minute can baffle most of us. Yet, roughly 4 million people in India alone have never experienced electricity in their household & still remain in the darkness ! It is simply impossible for regions with large populations to sustain a reliable grid providing electricity to each household. What can be done?
Solar home systems are basically electric generators which can be utilized to provide energy for running various appliances in the daily routine of a household; these systems are powered by the sun.
These systems simply convert the light energy from the sun into electricity which can be utilized either instantly or stored away in a battery to be used later.
A stand alone solar home
A typical solar home system is shown above which incorporates a solar panel on the rooftop, a battery, the electric appliances desired to be run and a charge controller/regulator which controls the current circulation between the panel, battery & appliances. To run A.C devices, an inverter is plugged into the charge controller. This is because solar panels produce only D.C Power.
There are 3 types of solar home systems available:
- Stand-alone solar homes – These systems are ideal for households with no grid connectivity. Solar energy is solely utilized to power the households.
- Grid Connected solar homes – These systems are ideal for urban households, where a part of their electricity demand (mostly during the daytime) is supplied by solar panels & the grid provides electricity during evenings and nights when solar panels cannot produce power.
Grid Connected Solar Home
- Hybrid Solar homes – The latest breed of solar home systems where solar energy is coupled with an additional renewable energy source (Example: wind, biomass) to provide electricity to households. These can be used both as standalone systems or grid connected systems.
Benefits of Solar Home Systems
The 3 categories of solar home systems discussed above offer a large bandwidth of solutions to the end user, from which one can pick the ideal option suitable for the household. These different systems make solar home systems universally acceptable and applicable to every household.
Stand-alone solar homes have been picking up market in the developing regions like India, China & Africa where grid connectivity for every household is simply not feasible owing to the large investment required to stretch transmission lines & the limited resources of coal to provide electricity for all. The Indian Government has already initiated a National Solar Mission in the year 2010 aiming to spread 2000 MW of solar energy through stand alone solar systems in off-grid areas by the end of the year 2022 .
Grid Connected solar homes are gaining popularity in urban areas around the world, to reduce their monthly expenditures on electricity bills & progress towards a more sustainable style of living. The concept of Net Metering has been introduced in the United States. Through this system, solar power is provided as a primary energy source to power household appliances. When solar energy falls short, excess electricity is pulled from the grid. The real benefit of this scheme is the concept of selling the excess solar power back to the grid at times of low electricity demand. This helps the end user and the electricity board accountable for every unit of electricity produced & used .
The environmental impact of solar home systems is hugely positive. 1 Kilo Watt (KW) worth of solar panels producing power for 5 to 6 hours a day can prevent emissions of 1.3 tonnes of CO2 annually , while a coal based power plant produces 1.6 tonnes of CO2 for the same amount of power generated . Hence switching from a coal based power plant to a solar based power plant could prevent 3 tonnes of CO2 emissions utilizing just a 1 KW plant!
Limitations of Solar Homes
Solar Homes have been a challenge to implement on a large scale due to their high initial cost. For the kind of energy consumption an average household has today, a standalone solar system is expensive to establish. Thus, solar homes are recommended today mostly for energy efficient lighting (CFL’s & LED’s) & limited hours of use of televisions and computers.
Households are sceptical to shift to solar homes due to common misconceptions. The most common misconception is concerning the limited life of a solar home system. Most people today think that a solar home system is sensitive & incapable of operating for a long time. This misconception is caused due to lack of simple maintenance procedures & lack of after sales services by the implementing organization which kills the system. A solar panel can produce power for a period of at least a period of 25 years!
Standalone Solar Systems face a technical challenge of energy storage, as batteries today run for a limited number of cycles compared to solar panels & suffer from power losses.
Mapping the Future for Solar Homes
Solar homes are not the future anymore. They are the present & they are here to stay! In 2010, solar systems worth $ 6 billion were established in the United States of America alone & by the third quarter of 2011, the demand for these systems grew by 140% !
For solar home systems to flourish in each pocket of the global economy, the role of Governments will be crucial. Programs like the National Solar Mission in India & the concept of Net Metering in the U.S have been hugely successful. Such schemes should be encouraged around the world to spread the benefits of solar homes. Credit policies & subsidy programs are crucial to create new markets for the solar industry at this stage to avert an energy crisis in the future. Solar homes have to be promoted as a mainstream energy resource to build the credibility of the technology it deserves.