Glasshouse growers have been urged to consider switching to renewable heat sources to capitalise on Government incentives.
The Renewable Heat Incentive (RHI) "is offering serious money", industry advice body GrowSave energy specialist Tim Pratt told growers earlier this month. Meanwhile, his colleague Jonathan Swain added: "It's the Government's way of boosting uptake of renewable heat. But they are still way under budget."
The principal fuel source for such projects continues to be biomass, for which "we are seeing a lot of interest", said Pratt. But Swain warned: "When RHI opens to the domestic market, the price of fuel will go up, particularly for wood pellets, from the £200 a tonne they cost now."
Pratt recommended that growers intending to invest in biomass secure three years' guaranteed supply first. But Swain added: "A lot of suppliers are willing to sign those contracts."
Given that the RHI rates for "large" (above 1MW) boilers are lowest, "there are far fewer of these", Pratt said, but added that an improved rate is likely to be announced later this year. Meanwhile, rates for small and medium models fell slightly at the start of this month.
A 1MW boiler costs around £400,000 "and other things add to that, from meters to a new shed", said Pratt. He warned: "Some people will even offer you free boilers in exchange for your RHI payment, but you are way better off if you can borrow the money."
Alternatively, ground source heat pumps "are becoming a lot more attractive for glasshouses", said Swain. "They work most efficiently at 50 degsC water output. For anything hotter than that, you will still need your boiler."
Pratt added: "If you have a borehole, you can use non-potable water. Or abstracted water - you are not removing water, nor are you putting it back heated. But they do use a lot of water."
Meanwhile, Climate Change Levy rates have changed since April and growers can claim a 90 per cent discount on this part of their electricity bills, up from 65 per cent. "It can be backdated, but it's a painful process," Pratt pointed out.
On conventional fuels, he said: "Gas prices may become more volatile given problems of supply so far this year." He added that he is sceptical of shale gas providing a cheaper alternative. "It's quite a few years away and when it does come they will just chuck a lot of carbon tax at it."
Technology updates Seminars and visits
GrowSave is holding a further seminar on biomass for edible crops in Hertfordshire on 30 July.
The industry advice body is also running a visit to glasshouse edibles growers in Canada in September looking at new technology allowing clean carbon dioxide extraction from biomass flue gases.
Then in October it is organising a tour of Denmark, a country with long experience of using biomass boilers.