What is biomass fuel – wood pellet boilers

Biomass boilers are well recognised, but what do they burn?

In the UK the introduction of the Renewable Heat Incentive has meant that the definition of biomass fuel has become more difficult to understand. The main driver for this are the emissions that the boilers have in addition to CO2 being of acceptable levels.

These limits are 30 grams per gigajoule (g/GJ) net heat input for particulate matter and 150g/GJ for NOx.

Each boiler range has to be tested with the fuel that is going to be used within it. Each fuel has a definition.

Wood Pellets

Pellets are the most straightforward for a homeowner as there is an ENPlus quality standard market on bagged pellets or on the website of the pellet producer.

http://www.enplus-pellets.eu/

All accredited wood pellet boilers have been tested to a European Standard EN303-5, met the standards of the UK Microgeneration Certification Scheme, and have a valid emissions certificate. Key to this is that the boilers were tested on ENplus pellets. So these are the only pellets that you can buy and use. To claim your RHI you will have to keep records and be able to show that you are burning ENplus pellets.

Wood Pellet Boiler Product Example

Pelleburn 15kW wood pellet boiler  will burn ENplus pellets only. When it does this it has been tested to show 9g/GJ for Particulate Matter and 81g/MJ for Nox. You can find a copy of the emissions certificate here. http://rhieclist.org.uk/wp-content/uploads/2014/04/NES_PLB_RHI.pdf

Wood logs

Logs are measured by moisture and by whether they are “virgin” or used. This potentially creates 4 categories.

Virgin timber – Very dry or kiln dried logs or logs with less than 25% moisture

Used timber – waste wood with no contaminants e.g. Pallets, or waste wood with contaminants e.g. MDF, Plywood, Chipboard

Wood Logs product Example

Pyroburn 30kW gasification boiler can burn wood with up to 25% as it was tested on wood with a moisture content of 12.01 percent. Had the wood in testing been much drier, e.g. 6% then there would be a limit of 12 percent dry wood in the boiler. http://rhieclist.org.uk/wp-content/uploads/2014/05/NES_PB_RHI.pdf

Wood burns much better and cleaner when the wood is dry. The testing process and regulations ensures that if you buy and use a log boiler you take care of what you put in it. For instance the following are attractive, but not allowable

  • Newly cut timber in excess of 25% moisture.  Fuel that you “find” in woods, or offcuts from timber merchants, or branches from a tree surgeon. This fuel will not burn well. You do not get the heat but your neighbours get the smoke.
  • MDF, Chip board or painted wood may burn, but it gives off lots of fumes. Unless there are very specific cleaning processes within the boiler to deal with paints and glues then the fumes produced will be toxic. This category of fuel (B2) cannot be burnt in the majority of boilers, and certainly no domestic or small boilers.

Logs can transformed into wood chip and sawdust and is subject to the same categories as above. Wood chip is generally quite bulky, so produced in local areas rather than pellets at one or two places. It varies in quality and next year (2015) suppliers will need to state that their fuel meets both a moisture standard and has no contaminants. We are excited about our new boiler The CB 160 which will shortly be released into the UK market.

Sawdust does not burn well and can cause back burning (fire can go back through the fuel delivery mechanism) boilers will specifically state whether they can burn sawdust or not. For instance the Catfire range of chip boilers can burn sawdust and has a mechanism to prevent backburning of sawdust.

Sawdust or shavings can also be made into briquettes easily (and pellets, but not so easily) that can burn very well and burn in most boilers.

As part of understanding the moisture content of the wood you would need to have an adequate storage and inspection process. For instance with pellets you need to check that there is not too much sawdust. For wood you will need to store so that the wood can mature. For chip you will need to keep it for a short period to ensure that it does not compost. Other than pellets, you will need to get a moisture meter to make sure that your wood is less than 25%.

Summary

If you want to install a biomass boiler you can only burn the fuel or fuels that it has been tested with. You will have to buy these fuels from accredited suppliers of biomass products from http://biomass-suppliers-list.service.gov.uk/find-a-fuel .

If you want to use your own stock of fuel you will have to self-certify and keep more detailed records. Again the fuel must relate exactly to the fuel tested on the boiler.

If you have questions about any of the above then please get in touch as we would be happy to help.


Domestic Renewable Heat Incentive – update

The domestic Renewable Heat Incentive is currently waiting for its final details from the government. These are expected during the summer of this year with the scheme going live early in 2014.

Further details can be gained from here

Among the key points are that the government is reconsidering the tariffs. This includes a possibility of increased tariffs for some technologies.

Currently the domestic tariff for biomass is projected to be between 5.2 and 8.7p per kWh over 7 years. For a 20kW installation this could mean £16000 over 7 years.

This does not compare as well as the non domestic Renewable Heat Incentive where the same installation could get a similar tariff over 20 years ie in excess of £40,000. However you would probably pay for your installation and financing as per the government report depending on the boiler and facilities that you want from your boiler.

Whilst we are waiting for the government to announce what they want to do we are finding that customers are changing or tailoring their installations to suit the delay.

In discussion with customers have found that a key difference between commercial and domestic is the issue of a pellet store. On smaller installations it is easier to poor pellets more frequently into a boiler that has an internal hopper or a smallish hopper that sits next door to it. If you want to build a hopper or buy a larger hopper the hoppers can be reasonably priced. For instance an 8 tonne external hopper can be about £2000. You then have to consider how to feed the pellets from the store to the auger. This can be a further £950 for a flexible auger of 3 or 4 meters. Alternatively you can use a vacuum system, where prices can start at £2000.

The payback of a boiler without a large hopper is much greater, but you have to poor in pellets on a more regular basis. It is possible to do this in the short term with a view to putting in a larger hopper as and when the RHI is confirmed.

The other trend we have seen is that wood boilers are being more carefully considered. For instance logs can be purchased in the South West from Longleat

Log Type Price
Hardwood Logs from £130.00 per tonne Delivered
from £116.00 per tonne Collected
Softwood Logs from £101.00 per tonne Delivered
from £87.00 per tonne Collected

These prices are considerably less than wood pellets and affect the payback of an installation project.

Mass produced fuels have gone up in price over the winter with oil reaching 65p a liter as the cheapest alternative to gas.

Our WBS boiler can accept a wood pellet burner. You can start with a log boiler and upgrade to a pellet boiler at a later date.

Both the above ideas are a move to keep costs down as te main driver for everyone is cost.

At Ecobuild this year we exhibited our Pyroburn product that gives an alternative to a straight log burner.

Log gasifying boilerIt is available as an 18, 25 and 40 kW boiler. It is attractively priced and can be an alternative to the WBS active range.

The other development is the “Duo”, now a live product, we visited the factory 12 months ago to see the product in the final stages of development.

duel chamber burning boiler

 

You can see a Dual chamber boiler video by following the link.

So we are finding that fuel prices are increasing – and this makes biomass more attractive, and logs or alternative fuels even more so. Well priced boilers and installations are met with approval, however we would all like to see a final version of the Domestic Renewable Heat Incentive confirmed soon!


Germany’s Renewable Energy accounts of 25% of total, and 5.7% is Biomass

Germany is one of the world leaders when it comes to renewable energy, and roughly half of the solar panels in the world are in Germany. That’s quite a lot. With such a strong focus on renewable energy, Germany’s Renewable Energy supply are getting rid of nuclear, phasing out coal, and trying to reach 80% renewable energy by 2050. They’re even building a large off-shore wind farm to generate even more energy.

It’s safe to say, that Germany is leading the way for the rest of us. They understand that there’s a time limit on how long we can rely on the likes of coal, gas and nuclear, and are finding a way to move forward.

Germany’s renewable energy output has reached an all-time high, of 25%. One of these ways is by using biomass energy to effectively burn waste products, and then turning that energy into heat and electricity and powering the national grid.

What’s fascinating about this though is percentage of energy which comes from biomass. Currently, it’s 5.7% of Germany’s energy supply, which is just over one fifth of their renewable energy, which might not sound like much, but allow me to put that into context.

We’ve already established that Germany hosts roughly half of the world’s solar panels, but by comparison, they are providing only 5.3% of the national energy. So as it stands, Germany are seeing more power from biomass, than they are solar, which gets you thinking, what makes biomass so special?

If you would like to learn more about Biomass energy, then click here. And if you’d be interested in finding out how you can bring biomass into your home with Wood Pellet Solutions, come and fill in a contact form here, and we’ll happily get back to you.


Training and Development

In between our daily workloads we have been busy developing our know how.

On Friday 4 of us will be training with Solar Focus in Oxfordshire as part of our installer partner relationship.

Next week Mark will be training with EDS to develop his knowledge of solar thermal systems.

Early in Feb Adrian will be trained to install solar pv systems.

Last week I was in Bulgaria with Sunsystem for the second time, and this time being trained on their biomass products.

This has meant that Renewable Living will be developing what it does. We do work closely with Green Phoenix and will now be installing solar thermal and solar pv products for them in this area.

Ecobuild was booked a little while ago and we are helping Sunsystem develop the UK market for their appliances. Solar thermal, Solar PV, accumulator tanks, wood pellet boilers and wood boilers. There will be a separate website that showcases what products will be available in the UK. Again working with Green Phoenix (see new products on their site) to provide the expertise around solar, we are enjoying a very busy period at the moment.


Wood Pellet Boiler Installations – Some General Rules

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

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.


Renewable Heating, Carbon Reduction and Wood Pellets

Renewable Heating – Wood Pellets have a carbon emission figure of 0.04 kg per kWh. This helps an organisation calculate carbon savings against oil or gas.

A home can work out how much carbon they are saving and understand why the Renewable Heat Incentive has been developed.

This compares against other technologies:

Heat pump with a COP ratio (see previous article) of 6:1 then the carbon emissions would be 0.53/6 = 0.09kg per kWh.

Heat pump with a COP ratio of 3:1 then the carbon emissions would be 0.53/3 = 0.18kg per kWh.

Oil is 0.265kg per kWh
Gas is 0.194 per kWh

If you are currently on Oil heating and use 20,000 kWhs of heat per year (average house) by converting to wood pellets you would save:

(0.265-0.04) kg per kWh ie 0.225kg per kWh

There are 20,000 kWhs in this example so a carbon saving of 4500 kgs per annum.