Introduction

Why use wood fuel on your Farm or Estate?

Wood fuel heating is a very attractive prospect for the farms and estates sector, where you are in the unique position to be able to produce your own fuel, often using home grown timber. Even if there is no timber available from your own land, you can be well placed to buy locally sourced round wood and process this in-house into wood chip fuel. Either way, the end result of producing a very low cost heating fuel is very achievable.

This ensures that wood heating can be extremely financially attractive, dramatically reduce carbon emissions and make the best use of local resources.  Wood heating will also give you an incredible feeling of satisfaction.

At HWE we know exactly what it takes to deliver successful projects on farms and estates.
We have developed this guide to assist you in understanding the economics, practicalities and other implications adopting wood fuel heating, and how this may work for you.
 

Benefits

One System, Multiple Benefits.

If your farm or estate currently spends more than £3,000 each year on heating bills then it is likely that a biomass heating project will offer you a number of advantages:

1. Make financial savings on your heating bills and receive a very attractive return on your capital investment.
2. Reduce your carbon dioxide emissions by up to 80%.
3. Reduce your reliance on imported fossil fuels which are imported, running out and which can fluctuate wildly in price.
4. Add value to your own timber or the local roundwood resource.
5. Feel satisfied that you are benefiting from your own resource and creating an independent and sustainable future.  

What are the economic benefits?

The capital cost of installing a wood fuel heating system is more expensive than an equivalent gas or oil fired system.  It is therefore through the running cost savings and pay-back period where the economic case is made.

The capital cost of installing a wood fuel heating system is more expensive than an equivalent gas or oil fired system and therefore it is through the running cost savings and pay-back period where the economic case is made.

Farms and estates are uniquely positioned in that you have the ability to produce wood fuel very cheaply in-house. The table below outlines the typical cost of producing wood chip fuel. (Log fuel will be cheaper to produce as there is no chipping cost, though the manual labour input required will be greater.)
  

The cost of wood fuel produced per tonne is also expressed above as a cost per kWh and this can therefore be compared with cost of alternative fuels as below;
 

As demonstrated by the table above, the wood fuel produced on farms and estates should be significantly cheaper than the existing alternative (for example up to 70% cheaper than heating oil).

Buildings or groups of buildings which have a higher heat use will therefore produce the best economic case.

The table below estimates the running cost savings achieved by switching to home produced wood chip fuel for some example installations.  Please note that these examples savings are shown before the impact of the proposed RHI (next page) is taken into account.  

Is there grant funding or government assistance available with the capital cost? What impact will the proposed ‘Renewable Heat Incentive’ have on the economics?

At the time of writing the government is consulting on the proposed introduction of their ‘Renewable Heat incentive’. It is proposed that the current system of capital grants is abolished and replaced by a revenue payment based upon the kWh heat output of the system. For example, in the case of the ‘very large house/castle’ referred to in the previous page, this payment would be £0.065 per kWh, and therefore an annual payment of between £13,650.00 and £31,200.00 for a total of 15 years.

The ‘RHI’ is due to begin in April 2011, though will apply to systems installed after July 2009. It is likely that the RHI will have a significant positive impact on the economics of your project as it is calculated to offer a 12% Return on Investment. Please contact us if you would like to discuss this further as we have been actively involved in the consultation process including presenting the industry and customer perspective at Government organised events.

In the meantime, enhanced tax relief is available on biomass systems through the ‘ECA’ scheme:
www.eca.gov.uk

Interest free loans are available through the Carbon Trust and we are a recognised Carbon Trust Partner.
 

What are the other benefits?

Sustainability and Satisfaction.

Using sustainable timber stocks grown in this country to produce fuel provides a sustainable heating source, and reduces our dependency on unsecured fossil fuel supplies. Similarly reducing your buildings dependency on fluctuating cost fossil fuels will mean you can accurately budget for energy costs.

There is also the added advantage of the personal satisfaction associated with heating your own buildings from your own, or local, fuel.  This will put a smile on your face!

Carbon Savings.

Approximately 80% of a building’s carbon emissions are from heating and hot water production. Displacing fossil fuels with wood fuel will therefore reduce your carbon emissions dramatically. For example, the average farm and estate project involving  the heating of a large house and 2 cottages will save around 30 tonnes of CO2 each year.

Wood Fuel Choice

Which type of wood fuel should I use, and how much will I need?

Farms and estates, producing fuel in house, will use wood chip or log fuel, as opposed to buying in pellets from an external supplier.

For larger buildings or groups of buildings we would recommend that wood chip rather than log fuel be used. The practicalities of processing, handling and manually loading logs mean that this becomes quite labour intensive for larger quantities.

Wood chip on the other hand can be loaded into a bulk store which self feeds to the boiler via an auger mechanism, therefore eliminating any manual intervention.
 
The table below outlines the quantities of wood fuel likely to be used in example situations.

Using Wood Chip

How Do I Produce Wood Fuel?

Generally speaking, wood fuel, either in log or chip form requires to be dried to a suitable moisture content (below 30%) before it can be used as boiler fuel for boilers rated below 150kW.

For larger boiler plant (up to 500kW), fuels up to 40% moisture content can be used, though in reality, the drier the fuel the better the operation of the system.

For wood chip fuel, the particle size must also be suitable (usually below 50mm square) to suit the feed system.

The process for producing wood chip fuel therefore involves:

1. Timber Sourcing and Delivery to Chipping Site.  This can be either wood sourced from your own supplies or bought in from a local source.
2. Seasoning of round wood: Drying of round wood to a suitable moisture content can be achieved by ‘seasoning’ the logs in the open, ideally for 12 – 18 months. Without a mechanically aided drying system, it is very difficult to season the wood when it has been chipped.
3. Chipping and Storage: Once seasoned, wood chip fuel can be chipped in bulk, into the bulk fuel store. It is usually not necessary for a farm/estate to go to the expense of buying a chipper, as a contract chipper can chip up to 150 tonnes in a single day. (Sufficient to heat a large castle for a whole year!)

Fuel Storage and Delivery

How do I store the fuel for the boiler/ how do I transport it from the bulk fuel store to the boiler fuel store?

There are a whole host of options for transporting and loading wood fuel into the boiler fuel store. This is a crucial area. If it is well thought through and planned, you will be able to minimise fuel handling and maximise the usage of equipment and storage you already have. If not, this can leave you needing to do a lot more work than you should be!

There are numerous options for handling and delivering fuel, a sensible approach is to keep it simple and make use of the space and equipment you already have available. For example, farms and estates often have tractor/loaders which are very useful for fuel handling.

We have outlined some of the main options for a farm or estate on the following pages, the capital cost of these solutions will vary.
 

Wood Chip Delivery: Front End Loader

These fuels stores can either be constructed on site (for example using block-work) or provided as part of a pre-fabricated store. These can be located either internally or externally, immediately adjacent to the boiler. Alternatively, the fuel store can be provided as part of a complete ‘packaged’ system.
This arrangement is suitable when:

• You have access to a front end loader.
• Your bulk fuel store is <300 metres from woodfuel heating system (Avoiding long return trips with front end loader)
 

Type 1: Above Ground Outdoor Store

Type 2: Above Ground Indoor Store

Larger Above Ground Stores

These options generally store larger quantities of fuel in the hopper which are automatically fed into the boiler.  The High lift trailer option allows the bulk fuel store to be further away from the boiler and hopper.  Chipping directly into the hopper generally requires more manual work than other methods but can be effective in some scenarios.

Type 3: Above Ground Fuel Store - High Lift

Type 4: Chipping Direct to hopper

Tipping Directly into below Ground Fuel Stores

Tipping directly from tipping trailer into the fuel store can be achieved either by constructing a below ground fuel store or alternatively, building this into and existing embankment or using a ramp. This is a convenient way of delivery bulk quantities of fuel, though this system is likely to require reasonably extensive civils works.

Type 5: Natural Drop

Type 6: Custom Underground

Technical

Management

How much maintenance is needed?

In addition to fuel supply management, wood heating systems require ongoing ‘routine maintenance’ (such as ash removal and visual checks) taking approximately 15 minutes per week, and an annual (potentially more frequent for larger systems) service. In general terms there is more ongoing management and maintenance required for wood heating systems than for fossil fuel systems.

HWE provide a comprehensive ongoing after care service through our service and support contract. This includes maintenance, call out and remote support services to ensure many years of successful operation for your wood heating system.
 

Next Steps