Barbados Light & Power Company Limited has faced criticism for restrictions it wants the Fair Trading Commission to approve via a Renewable Energy Rider on how much wind and photovoltaic generated electricity the grid should accommodate at any one time. The company’s Managing Director, speaking in a Let’s Talk exchange with the media this morning, said BL&P was being deliberately conservative in this regard because it feared that otherwise the national electricity system would be compromised.
To put the capacity issue beyond doubt, however, BL&P is hiring foreign experts to do an intermittent renewable energy penetration study and present the results before year-end. BL&P prefers no more interconnection of wind power and photovoltaic systems than 10 per cent of peak electricity generation on the grid, which is 16 megawatts.
“People have talked a lot about this capacity limit. Light & Power has made a recommendation that there be a limit to the amount of intermediate renewables that are put on the system and in summary it’s a question of simple physics really, it has nothing to do with what is perceived as a monopoly trying to inhibit the expansion of renewable energy systems into Barbados,” he said.
“We have a grid and to ensure that the grid remains stable we have to ensure that intermittency on the grid is managed… You have generators on one end at Seawell and Spring Garden and you have got the load spread out across Barbados. At every instant in time the load must exactly match the generation and that is our stable situation.
“Photovoltaic systems and wind systems are intermittent in nature, that is, when the sun’s there you get energy when there is no sun there is no energy, when the wind blows you get energy, when there is no wind you don’t get any energy. And you can’t predict in advance when the sun is going to be there and when the wind is going to blow so…, it goes up and down.
“What happens is that when you introduce that to a stable grid it impacts on the grid and it causes the grid to do up and down in a similar manner. When the photovoltaic or wind systems or not there … our generators have to pick up that load that is no longer being fed … and they can only respond at a certain rate,” he added.
King warned that if such a response was not forthcoming, and at the required rate, “the system will ultimately start to collapse and then your lights will go off, it’s as simple as that”.
“So that is why there is a limit to the amount of intermittency on any grid,” he said.
The official said in addition to its planned study BL&P was looking at other options, including batteries to store excess power, but he said the cost of this was prohibitive. But he insisted: “It is our duty, we believe, to try to maintain that grid as stable as possible and we need to be conservative in our limits on our recommendations and we believe that this will stand us in good stead.” (SC)