Today, solar energy has begun to shine: In many countries, it is the lowest-cost energy option, both from a household and commercial perspective, and even if external costs are not accounted for in fossil fuels and nuclear energy, solar energy is becoming more widely used within the utility sector.
In most markets, the share of solar energy is still less than 5%. Decarbonization through electrification in the heating, transportation and energy sectors offers many opportunities for the solar market, and the trend toward PV is one of both challenges and opportunities, with the industry buzzing about PV energy storage.
Solar accounts for 5% of today's EU electricity demand and will increase to 15% by 2030, with 20GW of new solar installed each year. another trend related to this is battery storage. in 2017, the first solar power plant without government subsidies opened in the UK, and nearly half of all household solar projects in 2016-2017 coincided with battery storage.
Energy storage is an important and flexible tool; storage can store power quickly and accurately, smooth out short-term fluctuations, eliminate maximum load power, and make solar energy readily available.
There are also economic advantages to PV + storage, storing solar energy when electricity prices are high and using it when prices are low, helping to stabilize electricity prices and reducing the cost of future upgrades and expansions to the transmission grid. In addition, it can also increase local employment and reduce CO2 emissions.
1. Photovoltaic storage to optimize solar energy supply
Solar supply curve (yellow) is the variable, and the traditional electricity demand curve (blue) only partially consistent, the combination of PV + storage can store excess power (white area), when the user demand is too high (blue area), the stored solar power can be transported back to the transmission grid, maximizing the technical potential of energy storage.
2. Photovoltaic storage to make solar output more stable
More stable means that the output of the solar system will not increase or decrease at a rapid rate. The benefit of solar & battery systems working in tandem is that short-term supply and demand variables are stabilized. PV storage can even make the solar system output fully distributable, i.e. available on the demand side.
3. Photovoltaic storage to provide auxiliary services
Auxiliary services allow energy systems to coexist with variables for up to one hour. In order to provide such a service, the generator needs to respond quickly to the signal and correct the frequency in fluctuations. The flexibility of PV + energy storage systems can provide faster and more accurate services for transmission system operators (TSO) and distribution system operators (DSO).
4. PV energy storage reduces network costs
Traditional transmission grids can only handle peak demand. However, more and more new generation transmission grids need to face both the supply side and the demand side. PV + energy storage system can greatly reduce the supply-side peak generation.
In Germany, a household energy storage system project can reduce the maximum output of a solar system by up to 40%, resulting in lower feed-in tariffs at peak generation. Supply optimization and energy storage measures can increase the capacity of the existing transmission grid, converge more renewable power and avoid network upgrades. PV+storage should have the right to make transmission grid connections, and the cost of fair metering should be clear in the user contract.
5. PV energy storage can provide more stable energy prices
PV+storage systems are able to gain revenue through electricity price arbitrage. When there is excess production, PV storage systems absorb power from the transmission grid at a lower price.
When electricity prices are too high, this power is re-delivered back to the transmission grid, reducing overall price volatility and simultaneously improving system reliability and operational capacity, which is feasible at both the system and household levels.
Different types of time-of-use tariffs can also apply, such as fixed tariffs, which vary with the number of hours of electricity used during the day, and variable tariffs, which vary with the market application of the day. Thus, electricity prices must be more variable and, more importantly, transmission grid charges should be taxed only once per kWh of electricity entering the transmission grid.