How Electric Vehicle Can Boost The Value Of Rooftop Solar

Solar technology is witnessing new advancements each day. One great thing is that these advancements are happening both in the industrial sector and the residential sector. One such new research has revealed how small-scale solar PV, batteries and EVs in combination can add value and drive mutual growth. Each of these technologies works great individually and hence scientists explored a way to work these three technologies together.

We see these technologies emphasizing each other behavior, given expected cost reductions; a close fit with energy sector trends of decarbonization, decentralization, digitization and democratization; and with energy and climate policy prioritizing electrification of transport and heating. Electric, transport and heating sectors are the holds the majority of releasing most greenhouse gases in the atmosphere. Integration of electricity, transport and heating technology is expected to help the decarbonization of the atmosphere affordably.

The scientists are currently focusing on Britain and Germany, as they are the most sought out EV (Electric vehicle) and solar market in Europe. As technology progresses, the developments are expected to trickle down to other emerging economies.

The report published looks at the opportunity to a near-term growth in residential rooftop solar panels, battery storage and electric vehicles. The report points out that batteries and electric vehicles can boost the economies of rooftop solar panels, by enabling consumers to use more of the solar energy produced, therefore increasing the savings on electricity bills. These savings have the potential to rise over time as the cost of solar panels, batteries and electric vehicle fall over time. In addition, the regulatory authorities can reform policies to let these technologies e review how regulators can reform grid services markets, to put these technologies on a level playing field with conventional generation, which further boosts income.

Electric vehicles are creating a new source of demand for solar powers, and the battery storage gives households further control of how you utilize solar energy.

The report noted that in Britain – where it currently takes whooping 19 years on an average to pay off rooftop solar. The Payback for a typical 4kW rooftop solar PV system when combined with 8kWh battery and small 35kWh electric vehicle, could be slashed to four years by 2025 and below one year by 2030.

In Germany – where currently the payback period is six years for a rooftop solar, the same-sized home PV-battery-solar combination would have a three-year payback by 2025, and less than one year by 2030.

Batteries and EVs can boost the economics of rooftop solar, by enabling households to use more of the solar power they produce, thereby increasing savings on their electricity bills. 

Solar Panel with BatteryThe Report Summarized

The report investigated four themes: The drivers behind the adoption of residential solar in Britain, the extent to which batteries and EVs can add value, the potential for grid services markets to boost adoption, and the impact on the adoption of continued cost reductions over the next decade. We summarize our main findings, for various combinations of market standard systems for residential solar (4kW), battery (8kWh, 5kW) and a small EV (35kWh). 

Solar feed-in tariffs and higher retail power prices in Germany result in a far shorter payback period for rooftop solar compared to Britain:

As said earlier, In Britain the payback period of rooftop solar panels is on an average of 19 years, as compared to 6 years in Germany. The stand-alone solar panel in Britain has an annual ROI of  -2.5% compared to +10.5% in Germany. But Germany is planning to phase out its solar tariffs from 2020, which would result in double the payback period to 12 years and diminishing the ROI to 1.5%.  After removing solar feed-in tariffs and export income, Britain is now also poised to scrap reduced VAT for solar and battery installations. Such a move would increase the upfront cost of installing rooftop solar panels by 15%, increasing the payback period to +20 years and diminishing the ROI to -3%. 

Smart Solar technologies can reduce the payback period to almost 10 years: 

The smart solar devices can intelligently operate high load situations like the electric heat pump which coincides its operations during the daytime solar generation. In this way, they help save electricity bills in Britain. They also help reduce the payback period in Germany. 

Adding an electric vehicle and/or a battery reduces the payback period: 

Electric vehicles in Britain generates a net savings of £700 (61494.96 Indian Rupee) compared to an equivalent traditional fossil fuel vehicle, paying the upfront cost in just 6 years and generating an ROI of 4% annually.  In terms of period back period, Germans serve a longer period of time, because of higher power prices and lower road tax savings. By providing a new source of power generation, electric vehicles promote self-consumption increasing the savings on electric bills. A combined solar-PV-EC system today in Britain has a payback period of 9 years and an annual ROI of 0.9%, In Germany, it is 7 years and ROI of 6.4%. 

Today Solar-battery-EV play on an uneven field with conventional energy sources: 

These markets offer incentive for electricity generation and storage that can help balance network demand and supply in real time. Today, they are in unfair competition with the giants of conventional energy industries. There are some battery service providers in Britain who offer a small incentive for customers to access their batteries for the sale of aggregated grid management services. The income generated by consumers in such a way is less, but if we double the amount in the near future, it helps the cut down the payback period from 14 years to 12 years. This is assuming that grid management service has zero income capabilities. In reality, electric vehicles are like to become a critical source of grid stability over the next decade. 

Combined rooftop solar-battery-EV systems could quickly become an obvious choice for households with available roof-space and EV home-charging: 

By 2025, it is assumed that, in Britain, the solar-battery-EV system could have a four year payback period, slashing to one year by 2030. Similarly, Germany could have a payback period of three years and one year respectively. This is assuming that there is no regulatory push from the government to provide solar energy rewards. The condition could get still more attractive if the regulatory authorities allow the consumers to sell the solar power in the wholesale market. 


We conclude that electric vehicles will an increasing potent driver of change in residential rooftop energy in the next ten years. Although, it can be said that much of what discussed above depends heavily on the efficiency of the rooftop solar system. The system must be designed to create maximum energy from the sunlight received. The consumers must be educated to buy the most efficient solar panel system.

Rooftop solar+battery+Electrical vehicle is supporting the societal shift from conventional energy consumption to a more prosumption behavior.

Amit Bajpayee is a Solar Energy Adviser and nature lover, currently working with Agni Solar. He is a passionate writer and love to write on topics related to renewable energy and solar industry to help people improve their solar energy knowledge and stay update continues.