How Much Can Wind and Solar Power Replace Oil Shale Electricity?
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PhD, Energy Expert
The Resolution of the Riigikogu that 100% of the grid electricity and 65% of all en-ergy consumed in Estonia will be generated from renewable sources by 2030 cannot realistically be met.
The notion of renewable energy covers two contradictory sources of energy. Combustion-free wind-solar power is pollution-free and free of charge. In 2021, it accounted for 2.1% of energy consumption. However, under the name of biomass, combustive fuels from agriculture, food and forest wood residues accounted for 92% of renewable energy, and in this, burning of wood formed 93%.
The growth can be achieved with wind-solar electricity, and in order to reach 65%, the production has to increase by 18 times.
Wind power 3500 MW (currently 300 MW) would cover the consumption of grid electricity during 30% of the hours per year.
1500 MW solar farms would cover the hourly consumption during 9.3% of hours. The development of solar energy is generation for own use.
In order to ensure supply security, it is still necessary to have 1500 MW peak load controlled generation operating in an uneconomic fluctuating mode. In some hours, there is a wind-solar power overgeneration, but this would cover less than half of the missing grid electricity through storage.
The increase in capacity will bring lower prices and the profitability of invest-ment is not guaranteed. Significant changes to electricity market regulation are needed.
The solution would be a permanent premium on non-combustion electricity to ensure a return on investment when electricity prices are low. If the price rises above the limit, the subsidy would be reduced.
The production, consumption and saving of electricity and heat energy cannot be regulated through a common notion of energy. The nature, consumption and sa-ving of electricity and heat energy are essentially contradictory. Each sector needs its own regulation.