How to make a successful transition from old energy systems to new, sustainable ones? Lessons from Denmark and Germany - seen as global pioneers of the energy transition - suggest the role of ordinary citizens is key.
2015 was a record-breaking year for renewable energy: Germany currently covers close to a third of its electricity needs with renewables, while Denmark is edging up on two-thirds.
In both countries, investments by ordinary citizens, farmers, and publically owned utilities have played a major role in developing green power.
In Germany, "citizens' energy" accounts for around half of renewable power capacity. In Denmark, that figure is 80 percent.
Both countries have used a system of feed-in tariffs to guarantee income to any entity generating renewable power.
"The government provided incentives for people to get involved, and they jumped onboard," said researcher Diana Süsser on the development of renewables in Germany. "People realized they could be not just consumers of energy, but also actors in the energy transition."
Süsser, a volunteer with Greenpeace, says this has been particularly true of areas in the north of Germany where communities got involved early, and where much of Germany's wind power is now generated.
But some experts are concerned that scheduled reform of Germany's renewable energy framework might work against such citizen energy.
Building public consent
Having ordinary folk pitch in isn't just good for expanding renewable capacity, experts say. It also means that they are truly invested in the energy transition, resulting in much higher levels of public acceptance.
Preben Maegaard of the Nordic Folkecenter for Renewable Energy says citizens' investments have made renewable power affordable in Denmark
This has been particularly important for wind power, which often faces opposition from local communities situated close to the towering turbines.
"Without the benefits and participation of citizens, there is resistance, and the wind installations are not built," said Preben Maegaard of the Nordic Folkecenter for Renewable Energy.
"The projects must be for the common good. Foreign investors who just want to install the plants and turn a profit are not wanted," Maegaard told DW at an international wind citizen energy symposium in Bonn at the end of January.
Rural communities in particular have caught on to the benefits of getting involved in renewable energy development: creating jobs and local added value, along with bringing in increased tax revenues, are among them.
In Mexico, wind power projects have been halted due to public pressure. Not because people are opposed to the idea of wind power, but because they are "against the foreign businesses that want to build major wind parks without the participation of the local population," said Sergio Oceransky, an energy expert from southern Mexico.
Oceransky therefore advocates cooperative wind power projects where profits are ploughed back into the local community. The first is planned for Ixtepec in Oaxaca.
Municipally owned power production, including wind, is also taking off in West Africa.
Ibrahim Togala of the Mali-Folkecenter Nyetaa described how in Mali, some 23 villages have local energy production with solar energy, and some diesel and biogas. He continued that in Senegal, there are already 400 villages with communal energy. "We working to further expand these projects," Togala told DW.
Also in Japan, where Fukushima turned citizens against nuclear energy, citizen energy in 2015 grew to a total of 180 wind power projects. "What we're experiencing now we call energy democracy: citizens want the right to their own energy," said Tetsunari Lida of the Institute for Sustainable Energy Policies in Japan.
People vs. profit
The German power market has traditionally been dominated by four major energy companies. But according to research by the Leuphana University Lueneburg, in 2012 utilities owned just 13 percent of the country's renewable power capacity (excluding offshore wind).
From families putting up solar panels on their roofs, to energy cooperatives in villages like Feldheim where communities band together to raise the investment needed for a solar or onshore wind park, ordinary citizens are producing 46 percent of Germany's renewable capacity (also not counting offshore wind).
The German Energiewende, or energy transition, is a high-profile political and social project in the industrialized country, with broad of public backing.
Communal energy advocates report that elsewhere in the world, lack of public awareness means it's the big energy companies that have the upper hand in renewable power development.
Neil Townsend, an energy expert with Just Energy, explained how in South Africa, there is a clear desire to electrify low-income communities. "But many people don't want to organize, they have little money to invest and don't yet realize the advantages of owning their own energy supply."
Big energy companies, on the other hand, have the financial clout to cash in on the growing sector. "They are smart, they have power and they get the contracts for renewable installations."
German citizen energy at risk?
Thomas Schomerus, a professor of energy and environmental law at Leuphana University Lueneburg, says that a new generation of wind turbines - exceeding 200 meters in height - are needed in Germany to meet the targets of the energy transition. But this could reignite public opposition.
"We have to face dramatic changes to our landscape," he told DW. "Public acceptance through citizens' involvement will become more and more important."
And reform of Germany's renewable energy policy framework could make things more difficult for energy cooperatives. The system of guaranteed feed-in tariffs for solar parks has already been replaced with an auction system. This is slated to be introduced next year for other renewable energy installations, including wind.
It takes money to make money. Big companies have more money behind them and can risk losing a bid, Schomerus explained. But energy cooperatives have a hard time competing in the bidding process. "If a local cooperative invests in the planning process and doesn't succeed, it's a big loss. They can't take that risk."
Collaboration not conflict
Schomerus suspects the German government may be introducing the new bidding system - published at the beginning of 2016 and due to come into effect early 2017 - to give the major energy companies that "overslept" thorough the energy transition until now a chance to catch up.
But he says the move could be "very dangerous" for the energy transition, since it doesn't take into account the energy cooperatives.
There might be a middle way: Schomerus hopes that in the future, big energy companies - which certainly have the resources to accelerate renewable development - will collaborate with citizens on renewable power projects.
"They haven't taken this opportunity so far - but they need to wake up. We have all these wonderful civil society initiatives - why not involve them?"