As we think of Solar Power it immediately come in our mind some kind of small lamps meant for villages and far flung areas. It mostly funded by NGOs or well meaning corporate and subsidised by Govt. So naturally it is assumed that it not an economically viable proposition. It is being promoted for thinly populated areas where grid connectivity comes at a very high cost. A good example is lighting up village helmets in Sunderbans delta supported by Tata Solar.

In all these efforts it is required to store power to be consumed in the night for lighting. In absence of modern lifestyle and not even cottage industry there is little requirement of power in the daytime.

Storing power is only possible in the form of storage battery most common type being lead acid battery. The problem is Lead Acid battery costs lots of money and its life is not more than 3 years if used efficiently. There is loss of power of at least 30% in just charging and discharging it.

All other form of energy is generated and consumed simultaneously. So same approach is required for solar. But then large solar cell farms need to be set up to generate sufficient energy which can be transmitted through grid. It requires large tracts of land a scarce commodity in our thickly populated country.

Solution is in allowing power generated from solar to be fed back to the transmission system from each household, factories etc. A house will need 2 meter one for consumption another for generation. One will pay for the difference. The power utility can have different buying and selling rates. It will require more transparent and accurate billing system. The power generated from households in this manner will be utilized for feeding offices, shops and smaller industries. A well managed utility company always knows its consumption pattern and it draws same from grid. This will convert each household into a tiny power house. As volumes will pick up the solar cell cost will crash. This differential power metering is already used in Japan. No wonder Japan produces & consumes world’s 50% of total solar energy. Our country with higher sunshine than Japan and can do much more.

It will reduce the transmission capacity needed for cross country grid. The utility company will need generation capacity to meet the difference of power. A more innovative method will be required to meet the evening peak power demand. A hydro electric is best suited to meet this peak demand. Small local area hydro units managed by local community can fill this gap where ever possible. In hydro plants total water storage capacity and water availability round the year is the main issue and not the capacity of the plant. So day demand can be met form solar and evening demand can be met form hydro. In cases where hydro plant is not possible another solution to this is gas based smaller plants of 1 to 5 MW. This kind of plants maintains very high efficiency at high variation of load. It means there is substantial saving in fuel cost in plant running at low load. This is not possible in cases of large size coal based thermal plants.

In any case to encourage conservation in the evening and more equitable energy use through the day a time dependent tariff is must. It will shift non essential energy usage to lean demand time. All most all European countries have time dependent energy tariff. This helps reducing heating demand in the evening and getting shifted to night.

In the end solar energy has not developed as an economical and viable option because 1st world countries have not invested enough in it as they do not have sufficient sunshine. Let’s look at an example. Our refrigerator have 1/4th space as freezer on top section. For 90% of middle class household it is empty. It is meant for storing frozen meat in west. So it is there in our fridges. Where as for 10 months in a year our primary use of fridge is for cooling water. There is no provision for a water tank and automatically filling it. An example of blind copying of west without even modifying to suit our needs. So how we can have extensive usage of solar cells if west does not? But it is not possible without regulatory support. Buying and selling form same house has to be permitted.