Large-scale daily storage, hydrogen as an energy buffer and a hefty back-up plant should make it possible to run the energy system almost entirely on solar and wind. That is the core of the energy plan The future Dutch full carbon-free energy system by the research team EnergyNL2050 of the Electrical Engineering Department of the Royal Institute of Engineers. The magazine De Ingenieur presents the plan in its latest issue, along with critical comments by some energy experts. In a new KIVI Energy Plan, our economy runs almost entirely on sun and wind. And it shows how to deal with irregular supply!
The plan rests on five pillars: substantial energy savings, wind and sun as the main energy sources with a smart mix, large-scale daily storage, a substantial share for hydrogen, also as energy buffer, and large back-up capacity
1. Energy saving
Energy saving lies mainly in preventing conversion losses. For instance, electricity production with fossil power plants has an efficiency of 45 to 50%; with wind turbines and solar panels it is at least 90%. A petrol or diesel car has an efficiency of 20 to 25 %, with electric driving it is around 80 % and with a hydrogen car with fuel cell it is always still around 45 %.
Something similar applies to industry. Cracking crude oil into petrol and diesel takes a lot of energy; soon this will no longer be needed. Heat can be supplied with heat pumps that harness heat from the environment. All in all, KIVI engineers foresee a saving of about 50% for our total energy system by 2050 through electrification.
2. Sun and wind
The main suppliers of that electricity are wind turbines and solar panels. To best accommodate seasonal changes - the sun produces less in winter than in summer, the reverse is true for wind - wind should produce four times more than sun.
Space for solar power can be found on roofs of houses, offices and industrial buildings, along (rail) roads and in solar parks on land or water. Wind will mainly be located at sea. This will require about one sixth of the total area of the Dutch part of the North Sea.
3. Day storage for short-term variations in energy yield
To prevent solar panels from overloading the electricity grid on a sunny day in summer, day storage is needed with batteries. The amount of these is comparable to the battery capacity of some 3 million electric vehicles. If internal combustion engines are no longer allowed after 2030, this is not at all an unrealistic option before 2050.
Day storage also helps cope with rapid fluctuations in wind energy supply.
4. Big role for hydrogen
A quarter of all electricity generated is used to produce hydrogen. This is mainly needed for industrial processes and heavy transport.
5.Back-up power
A hydrogen buffer bridges periods when the sun hardly shines and there is no wind. Fuel cells then supply electricity. That back-up capacity is comparable to about 20 large gas-fired power plants.
A lot of storage of renewable energy is needed.
The plan has its limitations: it has not been calculated in energy models and there is no financial justification. This is also echoed in the critical comments of the energy experts. They also point out that the plan underestimates what is needed for the electricity grid, and do see a role for biomass. On a particularly positive note, they mention that the plan shows what will be needed when we largely base our energy supply on solar and wind.
To read the full story on KIVI energy plan,
read the core of the energy plan: The future Dutch full carbon-free energy system
Want to read the full story on the KIVI energy plan from the March issue of De Ingenieur ? Then buy the digital version for €7.50 or - at a steep 25% discount - take a 12-issue digital annual subscription for €69
