The future of Belgian energy supply is  necessarily tied to the electricity network, since electricity will become the main vector for  energy in many industries (including transport and heating in the long run), according to Damien Ernst, a professor in the Department of Electrical Engineering and Computer Science at the University of Liège and holder of the EDF-Luminus Chair. But this is also the case because Belgium will soon produce only limited amounts of electricity, after having long been a net exporter. Damien Ernst doesn't see much potential in local renewable energy production.

To understand the challenge of electrical network management, we must first examine the energy context in Belgium and Wallonia. 

In Wallonia, 20% of primary energy needs are to be covered by renewable energy sources by 2020, which represents a production of 40,000 GWh per year. But in 2011, we barely produced a fifth of that amount! For Damien Ernst, professor in the Department of Electrical Engineering and Computer Science at the University of Liège and holder of the EDF-Luminus Chair, since all the hydroelectric potential has already been exploited and geothermal resources are practically non-existent, only three possibilities remain to develop renewable energy in Wallonia (and Belgium overall, since the situation in other regions is very similar): biomass, solar energy, and wind energy. Are any of these possible? And at what cost?

The lowest-profile industry, which has requested the fewest subsidies up to now, is biomass. There are two branches:  waste-based biomass (which produces energy from organic waste), and biomass crops (in which plant and forest products are used to produce energy). The first is only mentioned as a reminder since it seems to have very limited potential. The second one is more promising. "However it is quite controversial, and rightly so," claims the researcher, “it indeed raises a number of questions, not the least of which is the potential to increase basic food prices.” But putting these social and ecological considerations aside, is this a promising industry for the region? "In Wallonia,” explains Damien Ernst, "an energy crop produces 0.5 W/m2 of energy on average. We would need 2,000 km² of land to produce the same quantity of energy as a nuclear reactor such as Tihange, which produces around 1,000 MW. If we wanted to make use of biomass to compensate for the closure of three nuclear reactors in Wallonia, we would need to use 35% of our land to that effect!"

The second possibility: wind energy. Wind turbines currently only produce a fourth of what we want them to produce by 2020 (4,500 GWh).  And this objective still only represents half of the energy produced annually by a reactor such as Tihange. “Since a wind farm in Wallonia only produces 2 to 3 W/m², we would need to cover 6 to 8% of our land surface with wind turbines to compensate for the closure of the Tihange reactors. Is this even feasible given the current opposition to wind farms?”

Must we then focus entirely on solar energy? Statistics seem to support that option, since well-exposed, high-quality photovoltaic (PV) panels can produce up to 20W/m2, which is 10 to 40 times more per surface unit than the two industries mentioned above. Furthermore, PV plants generate fewer negative environmental effects and don't need to overtake agricultural surfaces since they can be integrated into buildings. "Currently, PV plants in Wallonia only represent about 25 MW of power,” says Damien Ernst. “But if we made use of all the well-exposed surfaces on buildings, we could reach 1,400 MW. We could double this power by using only 70 km2 of agricultural land to build solar farms." This industry definitely has potential. But Damien Ernst highlights one little-known downside of the solar industry. Because of its relatively high cost, it has been dependent on a policy of high subsidies. Reducing these subsidies would greatly decrease its appeal. "I worry that the expected returns of 4 to 7% promised by the Wallonia government will destroy the industry. Bankers already see the subsidy system as a toxic product. If you don't have the money to finance your facility, you will need to take out a loan, and it's very likely that your banker will turn you down even if you are eligible for the maximum rate of 7%. And if you do have the means to pay for your facility, a maximum interest rate of 4% will probably be too low and you will look for another investment vehicle. All the more so because this 4% rate is only provided to small facilities; larger ones aren't even subsidised! I believe that this incentive  system will spell the death of the industry.”  

Damien Ernst's conclusion: "I don’t think that the renewable energy sector will see any more significant growth in Wallonia (or in Belgium overall), and it may even disappear altogether!"