Viability of small off grid rooftop vis-a-vis utility scale solar plants
With increasing electricity bills and increasing trend to move towards less populated and outskirt locations, the need for rooftop solar plants is growing rapidly. There are two types of rooftop solar plants, on grid and off grid. There is very simple logic to choose between these two, and that is if you have 24 hour electricity available at your location with very rare power failures, go for on grid. On the other hand, if your location sees very less or no electricity, go for an off grid system. You can choose off grid, if your location observes multiple small power cuts instead of long power cuts because you would benefitted from continuous supply of electricity at your home with off grid when the grid is off, saving your electrical equipment from surges in process of off and on.
However, In this article, I am trying to find more reasons for promoting individual off grid rooftop solar systems instead of increasing solar capacity at large solar farms by power companies. Before moving forward I would like to set an expectation that these are my personal rationale to go with an off grid solar system and they may not be data backed or are still a topic of debate. Please comment to have healthy discussions around the problems and their solutions, not to defame one technology over another.
While introducing more utility scale solar plants is economically good for the end user because it would bring down the price per unit for them. In India, few recent power auctions revealed new low rates of 1.99 INR per unit cost to power companies. However there is some time in getting this benefit delivered to the end user because still the Solar power generation is very less compared to the overall power production by a utility power generation company. Till the time this benefit is passed along to the end user, would it make sense to pay seven times more for your electricity when you can get it for free (I know there is a capital invested which takes its time to recover)?
As many states have net metering facilities available to the consumers, people often go with an on grid solar system as it settles the electricity consumed with electricity produced first and then charges or pays back for the remaining one. This model works well but it more suits the big rooftop installations because they consume a lot of electricity and generate a lot of it. So economically this model is never going to benefit a lower middle class family while the rich people enjoy the most of the benefit. Rich can afford to install big solar systems and enjoy no or very low electricity costs and lower income group people (who pays electricity bills and not getting it for free) have to pay at the standard rate of electricity which may cost 3–6 times more than the rate at which it (only solar or renewable part) is costing power generation and distribution companies. People from these low income groups mostly consume not more than 1kw of power and even if they want to go with an on grid system, it won’t be allowed by most of the states because there is a minimum load that has to be there to support on grid installations. So they are again forced to pay more.
Now compare it with the off grid system. People who can not get a full on grid system installed because of minimum load requirements, can now install an off grid system with minimum panels. It would just cost the inverter and battery which these days is mostly available in budget for such low income groups. They can add up panels later as their economic position improves but they can start leveraging the sun power in their capacity. A 1kw off grid system is equally passing the benefits as a 10kw or bigger system would. With decreasing cost of batteries, off grid systems are becoming more economical and even there are few products in market which even eliminate the battery requirements from an off grid system which allows low income group people to start leveraging the benefits of solar power. Further, with latest policy changes by various states, gross metering coming into place, even slightly bigger off grid systems would start making sense.
Another point in favor of individual off grid systems is that it off loads the grid when there is surge in demand of electricity such as extreme heat days or festival or marriage seasons. An off grid system provides independence in case of natural calamities which are coming more often these days. I have read some time back that people having off grid solar systems on their roofs were able to use electricity after the flood hit the city.
One more aspect is that the bigger and bigger solar farms we are creating for supporting utility scale generation, we are increasing more risks to the environment. There are incidents across the world where big solar farms are causing deaths of birds because of various reasons like burning in focused sunlight or losing track of their path. Further, there is a probability of fires in these big solar farms which would cause very high economical losses and disruption in power supplies. The number of fire incidents in solar farms is increasing these days. Please note that the reason for the fire might not be solar panels or other parts of the system but solar panels provide good material to burn which increases the intensity of fire flames and no doubt has chemical hazard to the nearby places. Compared to individual rooftop installations, even in case of mishap of fire at an individual house, it does not cause disruption to the whole grid and at the same time it is comparatively easy for firefighters to deal with such individual events. With these individual rooftop installations it is less likely to cause problems to the birds compared to big solar farms.
Off grid systems also support the work from home trend these days because now you can go back to your native place where there used to be electricity problems. Practically you can live in your farm house or rent a resort villa which is powered by solar.
Before finishing the thoughts, I would like to mention that whatever system we are using, on grid or off grid, we should be conserving energy as usual. If we are getting electricity for low cost or almost free, we should still think that everything has a cost even if you are not paying that. For Solar or any other renewable energy there are many other costs that we are not aware of e.g. there is a big impact on the environment for preparing Solar panels or any other equipment we need for the system. The more we consume, the more it will have an impact on our loving earth. Save energy, save earth, save ourselves.