One of the hottest subjects in solar is how to integrate intermittent renewable energy sources with utility grids. Wind has recently reached 5% of energy production in California and a number of utility-scale solar farms will be in service in coming years to bring the total beyond 10%. It is a fundamental issue that has many utilities scratch their heads over, and that has spurred a series of new pilot projects.
Recently, Hitachi made an investment in the smart grid management company Silver Spring Networks. They are leading the smart grid pilot project in Hawaii, which has a contribution from solar and wind farms in double digits on some islands like Maui. I have done a search worldwide, and I actually found out that the grid with the largest relative amount of energy production from solar and wind is not in the Pacific but in the Indian Ocean. The French island of La Reunion already observes peaks of 30% of instantaneous power load from solar panels. The local utility operator deals with the challenge of intermittent energy sources every day.
Yet, there is time to develop solutions in urban areas because the massive load of a continental system, in the US or in Europe, can absorb daily variations. "A change in 40MW will not be noticed on the pan-European grid" explains Frederic Lefebvre of EDF-SEI, a subsidiary of energy giant EDF operating the grid on La Reunion. "We cannot use this first line of defense because a swing of 40MW here would correspond to four nuclear reactors going up-and-down in Europe."
The island has experienced a boom in the solar sector in recent years thanks to very favorable feed-in tarifs and tax credits. Some actually have pointed out the "financial bubble" that has led to errands, and the French Government curbed the incentives last year as a result. Despite the sudden slow-down, which does not help an island living mainly from tourism and other service industries, La Reunion has installed more than 100MW worth of solar panels compared to 20MW worth of wind turbines. Most of them are installed on industrial buildings.
"Variations from solar can be particulalry fast, in the order of 10 minutes, due to micro-climates on the island." explains Frederic Lefebvre. "In comparison, it is easier to predict the contribution from wind farms". EDF plans a day ahead the production of energy from fossil fuels, which still represents more than 50% of energy production on La Reunion. They are working on meteorology-based models to improve predictions from solar.
The second line of defense is to leverage diesel generators than can be turned on and off in minutes. In extreme cases, the utility is allowed to turn power off in some areas. That is a matter of last resort. EDF can manage the 30% policy target for renewable energies but estimates that with today's technologies there is a serious probability of black-outs for levels closer to 50%. EDF is allowed to cut solar power sources from the grid beyond the 30% threshold.
Renewable energy production is part of an important political program to achieve energy autonomy in the long term. The local eco-system involving EDF-SEI, energy producers like SIDEC and solar panel installers like Tenesol, is now part of a wider cluster in France called Cap'Energies. The Deputy Director of the cluster, Pascal Rioual, thinks that "we have a few years to be ready for this challenge and be part of sustainable renewable energy market based on grid parity".
It is theoretically possible to meet 100% of the energy needs of the island. That is the result of a study at the University of Louvain that looked at the case of La Reunion. The report on the various types of support schemes for island power systems was developped within the REFGOV project of the 6th European framework program in R&D. Below is a chart of how the full scope of renewable energy sources and storage technologies could power up the island entirely in 2050.
As solar and wind are getting close to fossil fuels in terms of costs -- with prices approaching 120 MWh -- it is a different game than when the sector was mainly supported by Government incentives. "Most of the solar cells installed on the island have been supplied from Chinese manufacturers in the last few years. Prices have come down significantly" explains Pascal Langeron, Manager of Indian Ocean Zone at SIDEC.
Sechilienne SIDEC is the largest producer of energy on La Reunion. The majority of their installations is based on fossil fuels but they have embraced solar in the last six years. They are also looking at integrating storage with future installations. "With 25%, we are the largest producer of solar energy on the island", Pascal Langeron adds. He welcomes a more mature market based on price competition and sees continuous albeit slower growth for the market leaders on La Reunion.
Solar and wind farms have been very useful to cope with the increase in energy demand year-over-year. As a result it has not really changed the carbon footprint of the island. Other cleantech approaches are important to make a difference. The island has no nuclear reactor and benefits from local resources. For example, fossil-fuel plants start to mix bio-mass in their production. It comes from the left-over of the local sugar cane industry and is called "bagasse". It only represents a couple of percents but it is smart way to deal with waste.
Historically, hydro-power has been the green source of energy on La Reunion that displays magnificent water falls and many rivers. It still represents more than 15% of the energy production and it is much easier to manage with valves. And the energy from the ocean is still untapped. Pascal Rioual reckons that energy savings are critical, particularly in metropolitan areas. "Advances in renewable energy production will not be enough across the board. Energy efficiency is the solution."
The island of La Reunion has embraced solar for water heaters to remove load from the grif, but it lags behind Greece and Cyprus. There are new directives in the construction and transport sector to consume less energy. In the Pacific, the island of Hawaii in the Pacific is following a two-prongue approach: increase renewable energy production to 40% and decrease consumption by 30% to achieve a net 70% clean energy production by 2030.
The current activities on islands of Hawaii and La Reunion give a snapshot of what is awaiting developped countries to really make a difference and fight climate change. "You have in La Reunion a concentrate of the technical and social challenges" notes Pascal Langeron. Fortunately, the population has been informed about the importance of renewable energy production and energy efficiency, and they are an important partner.
Actually, Reunionais did not welcome the change in tax incentives as it has threatened a number of new jobs on the island. Despite recent social protests against the high cost of living on the island -- the high price of gasoline in particular -- La Reunion has not been hit too much by the financial crisis because unemployment rates are already high at 30%. Solidarity is part of the social fabric.
Yet, they are looking at deploying electric vehicles powered by solar on the island. Tenesol is working with Renault and EDF is working with Peugeot. Subsidizing the solar industry in Europe is not sustainable, as Spain experienced recently, and a more integrated approach driven by grid parity is coming. Eyes are on the island of La Reunion.