As part of our service we assess requirements and properties to help you choose the right system or boiler for your heating and lifestyle choices. This post is all about Wood Pellet Boiler Installations.
For this we asked Tom Jacques, an architect and RIBA Client Adviser based in the South West for some comments.
Tom responded with 3 articles the third of which is below.
Part 3 General rules about wood pellet heating
Rule 1 – Most estimates on websites are unreliable
As the complexity of the system selected increases, the parts and the labour go up in price significantly. However the maintenance levels go down and the efficiency of the system goes up.
Expensive parts do include the pellet boiler which ranges in price from £3000 to £17,000 but also:
The flue – this can cost between £750 and £2000
Accumulation or climate control – between £850 and £2000
Pellet Store – You can use the integrated hopper that will last you a few days at peak load. Otherwise there are several options. A steel hopper may cost between £2000-£3000, as may a flexible liner in steel frame.
Pump sets and other plumbing equipment are also needed, especially if you have several heating circuits.
The labour charge varies from a few days to a couple of weeks depending on the design of the heating system proposed. This may be in the range of £1500 to £6000 with plumbing supplies (e.g. copper pipe) being extra.
Rule 2 – Everyone is an expert
We accept that the market is relatively new. Whilst most MCS accredited installers are very good and knowledgeable we have found that people’s knowledge varies. This includes consultants, other technologies, advice centres, builders, architects etc
If you have a budget and know what you want, do invite several companies to quote. Any risks that there may be can be identified and ironed out.
Rule 3 – Do the sums
We often suggest biomass as we think it has great potential as an alternative to oil and Lpg, particularly where heat loads are higher. Occasionally other solutions, including ground source heat pumps, air source heat pumps, solar thermal, and electrical generation and output devices may be preferable, or used in combination, and should also be considered.
All renewable technologies have the benefit of being able to have MCS accreditation. As such when your house is assessed, they should tell you how much heat you can get from their system, how much it will cost to install and run. It is then a fairly simple process of firstly doing the sums and then secondly having a feel about which technology you like best and works in your situation.
Key considerations for “doing the sums” are to:
- Understand your own heating needs. What heat did you use last year? For instance if you used 2000 litres of oil you burnt about 20,000 kWhs of energy. At 60p a litre this is £1200. This costs 6p per kWh
- Get a price for the equipment and installation along with the output or performance, probably in kWs.
- Understand how the equipment works at its best and its worst so that you can get an idea of operating costs. ie. how many tonnes of pellets do I need to burn? Pellets often release 4800 kWhs per tonne. In the above example this would be approximately 4.2 Tonnes of pellets. This gives a fuel bill of about £800 and a saving of £400. This costs 4p per kWh
For Heat pumps understand the co-efficient of performance (COP). For instance a heat pump will perform differently based on:
The type e.g. Air Source heat pump or Ground source heat pump,
The job it is being asked to do e.g heating water to 60 degrees C
The temperature of the air or ground where the heat exchange is taking place, and maintaining optimum performance.
Each kWh of “free energy” needs electricity to power the heat pump. If the COP is 2:1 then you get 2 units of heat for 1 unit of electricity.
A recent study of heat pumps in 2010 – “Getting-warmer-a-field-trial-of-heat-pumps” by the Energy Savings Trust suggested that the COP or Coefficient of Performance for heat pumps varied between 1.2 and 3.6 with a mid range of 2.2 for ASHP and 2.3-2.5 for GSHP. If electricity is 15p a kWh (then you would be paying between 12.5p and 4.2p per kWh with the majority of outcomes being between 6 and 6.8p per kWh ie a total bill of about £1200. Clearly if you had a PV installation with spare capacity or a “special” rate then you can reduce this cost.
Similarly, if the electricity is obtained through the mains, system losses will be taken into account in any calculation of carbon consumption and overall efficiency.
With the Renewable Heat Incentive, the rates for non domestic RHI have been published and this gives you an idea of the possible rates for domestic RHI in the future. Biomass is 7.9p a kWh, Solar 8.5p, and GSHP 4.5p. For 20,000 kWh’s of heat biomass wood pellets would gain nearly £1600 per annum for 20 years.
Rule 4 – The price of fuel will go up in price
Unfortunately we are in a volatile period for prices. Electricity, gas and oil are likely to keep going up in price. No one really knows by how much. There is greater demand for a diminishing world supply, resulting in a shortfall in the amount of energy to go around. In general oil and gas go up in price when you need it most.
Wood pellets are being made all over the country and there are more pellet suppliers than there are electricity providers (or gas and oil producers). This means it is a more competitive market which is likely to remain price sensitive for some time to come. Clearly there is a potential limit for how many wood pellets can be produced. The main constraint is the supply of raw material either sawdust or recycled wood. Many providers have fixed their prices to give confidence in the industry and it is very unlikely that you will get a monopoly in the same way as other forms of fuel. Still, it is likely to make more sense to order when demand is lowest.
For a good idea of relatively up to date price comparisons do click here
Rule 5 – Simple is best
With all the above points there is a tendency to get confused or wedded to a particular solution which may prove inappropriate, or to get consumed by too much detail at an early stage. Do take advantage of your home as it is. If you are combining alterations with an extension, consider how best use can be made of each element, and what can be best located where. Do ensure that you minimise heat loss as this is usually the most cost effective intervention which can be made. For systems installed do consider carefully how you will use and maintain the buildings and systems installed, for example the trade off between filling a hopper once or twice a week against once or twice a year (and the increase in costs that will result). Do use existing chimneys where possible as this will decrease your costs.
If biomass forms part of your solution, some of the choices you will make will be substantial and make a difference to the costs and effectiveness of the system. Other choices will be a bit like choosing a car. Once you have narrowed down the options by essential criteria, the remaining options will largely do the same job, but preferences can lead to significant price differences even within a model.
Installation costs are normally quite similar between companies for the same job, (it is worth getting alternative quotations to verify this), but the more complex the system, the higher the installation costs.
Tom Jacques is an architect and RIBA Client Adviser based in the South West.
Alongside interpreting,defining and meeting clients spatial and aesthetic requirements, Tom prioritises environmental design alongside an understanding of building physics, the use of appropriate technology, and the performance of buildings and their systems in use.
He embraces different approaches in different circumstances, and works where possible with specialists in their fields. Many of his projects involve work with listed buildings and in sensitive settings, and where planning and listed buildings consent is required.
He is not a specialist in any particular product or technology, nor a building services engineer, but is able to offer advice and assistance on projects where required.
If you wish to contact Tom, please contact us and we will pass your comments on to him.