Rainbow Growers reduces GB carbon emissions while generating substantial revenue


Energy Partner:Rainbow Growers
Location:Kent
Asset Type:Combined heat and power
Participation:STOR and Capacity Market
Revenue:Over £30,000 per annum
Capacity:5.4MW


“This is an important way to reduce operating costs and make more efficient use of our generating capacity...”

Pleun van Malkenhorst, Managing Director, Rainbow Growers



In 2009, Dutch commercial horticulturists Rainbow Growers entered the Thanet Earth greenhouse complex in Kent – which has enough glass to cover nearly 80 football pitches – and opened one of the largest single-unit greenhouses in the UK.

Rainbow Growers’ greenhouse is powered by two large gas-fired combined heat and power (CHP) generators. These supply heat and CO2 to the capsicum pepper crop. Unlike most of Flexitricity’s clients, only a small proportion of the generated electricity is needed on site; the majority is sold.

New revenues from existing assets

Rainbow Growers' two on-site CHP units, totaling 5.4MW of electrical output, operate when heat or carbon dioxide is required in the greenhouse. On average, just under half of this capacity is standing idle at any time, and this spare capacity is made available to Flexitricity. The site has a full parallel grid connection, allowing Rainbow to generate electricity at any time.

During idle periods, Flexitricity's smart grid infrastructure has the ability to turn on the generators at short notice. This helps National Grid to stabilise the national electricity network during demand peaks, or when large power stations fail. Heat generated by the CHP units is retained in heat stores for later use.

The revenue source - worth a significant annual sum to Rainbow - is enabled by Flexitricity, entirely from assets which the company uses day-to-day.

Getting on with core business

Rainbow Growers provides reserve electricity to National Grid only within the constraints of normal business operations. Flexitricity created elective arrangements, allowing Rainbow to opt in and opt out in accordance with its needs. Flexitricity understands that core business processes must always be protected, so the system operates only within pre-agreed limits, which are measured and checked in real time.

“This is an important way to reduce operating costs and make more efficient use of our generating capacity,” said Pleun van Malkenhorst, Managing Director of Rainbow Growers in Kent.

We obviously need to generate our own power. However our arrangement with Flexitricity means we are also deriving revenue from the plant, which helps towards our costs. In addition, this helps reduce carbon emissions.

“Flexitricity’s smart grid approach allows us to do this while we get on with our day jobs – producing great crops for UK consumers.”

Next steps:

National Grid has opened up the Balancing Mechanism, their most important tool for balancing the energy system in real time, to a wider range of flexibility providers. This presents a significant opportunity for flexibility providers like Rainbow Growers.



All performance claims made within this testimonial, both technical and financial, were true at time of writing. Claims relating to past performance of certain asset classes do not represent a guarantee of future results for assets in the same class or other asset types

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