3 Counties Wood Fuels


  • Leominster, Herefordshire

Project Included

  • 2 x 1MW Kalvis 950kW boilers
  • 4 x heat exchanger and fan systems

RHI Payments

  • A project of this size would gain an approximately £190,000 every year for 20 years, index linked to inflation

Total Project Price

  • £500,000


  • Approximately 3.5 years (combining RHI income & fuel cost saving)

* To protect client confidentiality, figures are based on an average of several typical projects of this size and all financial information are not specific to this project. Current information on RHI payments is for guidance only, not to be considered a guarantee.


Wood chip for drying


After renovating their family home and installing a Heizoack wood chip boiler, the owners saw a market for producing biomass fuel and used their knowledge and experience of sustainable timber harvesting to establish their new company.

David and Louis Saer diversified their timber harvesting business, Chalford Timber, which had been established for 35 years.

Today, 3 Counties Wood Fuels is a family-run business that sources round timber from sustainable sources, heavily supported by the Forestry commission as well as from private estates who manage their own woodlands.

As well as running the harvesting business and producing biofuel from their hub in Leominster in North Herefordshire, 3 Counties Wood Fuels is also able to offer impartial advice on switching to biomass, running and maintaining the biomass boiler systems, attaining renewable heat incentive (RHI) payments as well establishing and maintaining sustainable woodlands.

Wood chip to be dried and used as biomass fuel

The Challenge

3 Counties Wood Fuels had been looking for ways to reduce the drying time of its wood chip so as to increase its supply of the biomass fuel to its growing customer base and grow as a business.

Rainbow was approached by 3 Counties Wood Fuels to design and construct a 2MW wood chip drying system to supply heat via a concrete floor drying system.

Feed delivery system

Our Custom Solution

Rainbow supplied and installed two 1MW Kalvis biomass boilers connected via four heat exchangers and fan systems to deliver heat to the underfloor drying system. Our solution was a full turn-key installation with a high performing biomass boiler and a drying floor system that will see the company significantly grow.

Heat exchangers and fans

The Incentive

3 Counties Wood Fuels' main driver was to increase its supply of wood chip by significantly reducing the drying time required between each batch. This will also ensure the company is able to supply biomass wood fuel on demand to its growing customer base.

In addition to being able to increase its supply of wood chip, the company will also benefit from the Renewable Heat Incentive (RHI) scheme that will see the system generating approximately £190,0000 in payments every year for the next 20 years (index linked), which will work out to approximately £4 million over the course of the scheme.

Taking all of this into consideration, the ROI on this project will be approximately three and a half years.

Metal drying floor system to dry wood chip for biomass fuel

Forming part of Kalvis’ premium commercial boilers, the M-1 range of boilers have been specifically designed to offer the customer high output, low maintenance and fuel tolerance.

M1 boilers are ideal for large industrial applications, with a wide range of accepted fuels, including grain waste, pressed peat, sawdust, wood chips and pellets.

1MW M1 Kalvis biomass boiler for drying system

The Kalvis M1 series four-way boiler is the ideal boiler to generate heat for industrial purposes. There is a wide variery of suitable fuel for the Kalvis M1 boiler including sawdust, wood shavings, various types of pellets, pressed peat, grain waste, grain or other bulk fuel.

Main features of the Kalvis M1 boiler include:

  • Protection against overheating by balancing the flow of water in a heat exchanger.
  • Automatic combustion process control.
  • Evenly spreading and moving the fuel.
  • Automatic ash removal.
  • Pneumatic heat exchanger cleaning (optional).
  • The fuel is supplied to the boiler by an agitator or by a hydraulic fuel feeder.
  • The boiler can be transported in parts.

The boiler controller not only controls the combustion process, but also the:

  • fuel feed conveyor;
  • primary and secondary air fan;
  • drive shafts;
  • ash removal conveyor;
  • boiler recirculation pump;
  • boiler smoke;
  • dusts recirculation smoke (if fitted);
  • combustion process according to "λ" probe;
  • boiler room visualisation (optional); and
  • boiler service, remotely (optional).