“A human scale is needed to ensure public understanding of the energy transition.” Flickr.com / 10-10-UK CC-BY
“Small is beautiful” was the catchphrase of the alternative energy movement of the 1970s.
Gunnar Boye Olesen of the INFORSE energy network in Denmark still thinks there is a case for building on a human scale.
1974 saw a rising tide of anti-nuclear sentiment in much of the world. The alternative energy movement offered a far-reaching critique not only of nuclear but also of large-scale oil, coal and hydropower.
More than 40 years later, the alternatives are winning. Wind, solar, and biomass are standard options for new power production. All fossil-based and nuclear options are in crisis.
But what happened to the scale?
AN asked Gunnar Boye Olesen, of the International Network for Sustainable Energy (INFORSE), based in Denmark.
“A standard wind power turbine is now 30 times bigger than it was in the 1990s,” he admits and sees no way to turn back.
But, he points out, a wind park in the order of 10 megawatts is still very small compared to conventional coal and nuclear power plants.
A turbine is much too big for one family, but can be the right size for a community or a municipality.
“It can still be a community project and the neighbours should have a say in project design and siting,” he says.
Gunnar also doubts there is any economy of scale above tens of megawatts for renewable energy such as wind and solar. There are other reasons why big scale often prevails:
“When a community decides, they go for smaller scale than a municipality, and government decisions tend to favour still bigger scale, often above what is optimal, just because it is a simpler decision,” he claims.
Photovoltaics are decentralised by their very nature, but need balancing in countries like Denmark.
Denmark now gets two per cent of its electricity from PV, but very little in the winter, during power use peaks, notes Gunnar.
One move towards the very big scale is very long power lines, for example planned interconnectors between Norway-UK and Denmark-UK.
“There are admittedly many benefits of interconnectors in for example the Nordic grid,” he says.
Denmark gets about 40 per cent of its electricity from wind power. That is possible today thanks to balancing provided by Norwegian and Swedish hydro.
“But power lines are not the only solution. We have fought against some such projects. They should not be built without good economic evaluation. They are expensive investments and can take away attention and funding from local solutions,” says Gunnar.
The combination of small and big seems to be the optimum, at least for Northern Europe, he adds.
Alternatives to power lines, for balancing, can be more demand-side management, storage of heat, hydrogen, and also batteries if they get cheaper.
What about other renewables?
Combined heat and power for district heating and in industry, fuelled by biomass, is a medium-scale technology.
“But it will have less of a future than was thought earlier, due to cheap electricity from wind and solar.”
Geothermal heat (not electricity) is a medium-scale technology that has been developed in Denmark, but which the present government has abandoned. It still has a large potential, to supply 10–30 per cent of Denmark’s heating requirements, according to Gunnar.
Solar heat is also of some, even growing, importance in Denmark, in particular for smaller district heating systems, where large thermal storage tanks even make seasonal storage feasible.
As for biomass, it consists of several parts. Biogas, to replace fossil gas for vehicles, heat and power, is often smaller scale, in the order of 100 kW to two MW. Biomass for heat and electricity can be small-, medium- or large-scale.
“Biomass has another problem of scale: Very long distance high-volume trade (such as from USA to UK power plants) should be avoided, but there is nothing wrong with some trade, or even that for example Sweden becomes a net exporter,” says Gunnar.
“In a very centralised system, people lose contact, and social networks do not function well. A human scale is needed to ensure public understanding of the energy transition. So decentralisation is an objective in itself, says Gunnar Boye Olesen.