Hybrid solar plant: 24x7 power guaranteed

Israeli energy company AORA wants to prove it doesn’t have to be sunny all the time for a solar power plant to make electricity. To generate round-the-clock electricity, they are combining traditional fuel – such as biomass or diesel – with low-carbon solar power during daylight. AORA is constructing its first hybrid solar power station on a half-acre (0.2 hectare) plot in Israel’s Negev desert, in an attempt to tap into the multi-billion-dollar clean energy market.

The Negev plant, unveiled to the public this week at an energy conference in Israel’s Red Sea resort of Eilat, uses diesel for now. It will be online next month, producing 100 kilowatts – enough energy to power about 40 houses. The module comprises 30 large mirrors reflecting sunlight onto a generator on top of a 90-foot-high tower. It can shift seamlessly between using the sun as fuel and a conventional or another renewable fuel.

How it works?

One of the main hurdles in completing the hybrid power plant, however, was creating a generator that could handle concentrated sunlight that reaches nearly 1,000 degrees Celsius, said AORA’s operations manager, Yuval Susskind.

Aora, therefore, built a special receiver on a tower that’s capable of handling high temperatures. Using concentrated sunlight, air is heated in this receiver and then shot into a combustion chamber, where it expands and powers a turbine, producing electricity. A separate route can bypass the solar receiver and use a secondary fuel to power the turbine when necessary, allowing the power plant to produce non-stop electricity.

The process also creates a by-product of some 170kw of heat, which can be used to heat water for homes or factories. Because each of these units sits on just a half-acre, it can provide electricity in the most remote areas. You can build one outside a village, or have many together in a desert. A 100kw plant using traditional photovoltaic panels, which can have up to 15 per cent efficiency, would need twice the land, AORA said. Its hybrid-solar plant runs at 28 per cent solar efficiency.