The Biomass Boiler Alternative

Biomass Boiler

An Introduction to Biomass

Households that are not keen on modern renewable energy technologies might prefer a more traditional wood burner or biomass boiler. Man has been burning wood to provide heat since he first harnessed the power of fire in his cave, but a modern biomass boiler offers a more sophisticated solution to home heating.

Simple wood burning stoves provide heat and a focal point for the main room and can include a back boiler to run small-scale central heating and hot water systems. A biomass boiler works like a normal gas or oil boiler but they burn renewable biomass instead. New generation systems are easy to use and deliver greater than 75% energy efficiency using pellets or properly dried wood.

Systems are available for a range of fuels, including logs, wood chips, sawdust, grass-derived biomass pellets or even peat. The choice of fuel will be dictated by the availability and price of a reliable local supply and the type of storage available. The greatest savings are made when buying in bulk so to get the best deal a significant amount of storage space is required.

Pellets are much easier to transport and store than logs, and provide a more controllable heat. Pellet-fuelled biomass boilers are available with automatic fuel feeders and they can be programmed in much the same way as conventional gas boilers. Log-burning stoves and boilers involve considerably more work and are less controllable.

The installed cost of a wood burning stove will be around £2,500 to £7,500, depending on the model and the availability of a flue. The price of a full biomass boiler system is greater than that of a comparable gas boiler at between £10,000 and £20,000, depending on model, size and ease of installation.

After the initial outlay, the system should reduce energy bills over time, with some studies suggesting that a biomass boiler can save the average household up to £800 a year when compared with standard electric heating, or up to £210 a year compared with an old G-rated gas boiler. However, at typical 2018 prices, running a biomass boiler is likely to cost more than a modern condensing gas boiler.

To maintain efficiency, the flue will need to be cleaned annually at a cost of around £50. Another downside is the need to remove and dispose of ash. Some biomass boiler systems have automatic ash removal and compression systems that make the job easier.

Government support is available for the installation of a biomass boiler or biomass stoves with a back boiler through the Renewable Heat Incentive scheme. The income depends on the system and the amount of energy it produces but the payment for a biomass boiler in a four-bedroom, detached house may be nearly £2,000 per annum. To be eligible, the property must have a compliant EPC that is less than two years old.  There is a calculator and information on the BEIS website here.

How Long Will Our Gas Last?

EPC

On 1st March 2018, in unusually cold weather, National Grid issued a warning that the UK may not have enough gas to meet demand in the short term. The forecasted requirement of nearly 4,000 million cubic metres for the following day indicated a potential shortfall of approximately 50 million cubic metres. Wholesale prices soared.

The problem was compounded by a number of outages, some of which related to the cold weather. These included on-going problems with a pipeline to the Netherlands, reductions in crucial flows from Norway, and technical issues at the Barrow gas terminal in North West England.

Measures were put in place to procure additional supplies, manipulate the electricity generation mix and to reduce the industrial use of gas temporarily. Some major manufacturing energy users have supply contracts that can be suspended in this way in return for cheaper prices. Fortunately, the onset of warmer weather alleviated some of the pressure and the measures were successful in maintaining supplies to domestic customers on this occasion.

However, the situation had shone a light on the status of gas supply and storage in the UK. Gas storage capacity is at the lowest level since records began in 2006, principally because of the closure of Centrica’s Rough gas storage facility off the East coast under the North Sea. This had been responsible for some 70% of the country’s storage capacity.

Our own gas production form the North Sea fields is reducing, and while liquefied natural gas (LPG) is being imported through facilities in Kent and Pembrokeshire, market prices are increasingly pushing LPG towards a massive demand from Asia. Overall, our daily gas reserves are just a fraction of what they used to be.

Research in 2017 by the University of Edinburgh (here) suggests that recoverable UK oil and gas could run out by 2027. Some analysts believe that global stocks of oil will run out in 2052, and that we will need to use gas to fill the gap, meaning that those reserves too will be used up by 2060. Any new finds are likely to be smaller and more expensive to extract and transport.

A significant proportion of known gas reserves are held or controlled by countries that are not politically allied to the UK, and could hold western Europe to ransom. Others are in politically and socially unstable nations.

British shale gas companies suggest that they could save the day, and hope that UK fracking will finally begin in earnest in 2018. The British Geological Survey believes that UK geology has the potential to provide sufficient shale gas to meet our demand for 25 years, but in the face of opposition and conflicting expert opinion on how much will actually be extracted from the ground, fracking may not be a major or long-term panacea.

In 2018, research headed by an eminent geologist, Professor John Underhill of Heriot-Watt University, suggested that we have overestimated potentially extractable reserves as our tilted and folded geological strata are less likely to hold fossil fuel deposits than unaltered geology, and that any deposits that have formed have been dispersed into small pockets that make them less suitable for extraction.

So should households considering replacement gas boilers, heating and appliances be worried? Despite the price rises, gas is still a reactively cheap fuel. But with its increasing use for electricity generation as we phase out more carbon-intensive coal, and with the proposed replacement nuclear sources taking longer than expected to come on line, how long will the gas last?  And, if stocks dwindle, which of all of the eggs in the gas basket will get priority, electricity generators, essential services, businesses or domestic users?

Policy dictates that domestic consumers should be the last to experience deficits with business customers bearing the brunt of any shortages.  The projections suggest little cause for panic in the short term. Nevertheless, the gas supply system is beginning to show signs of fragility and it does not take much to push its resilience to the limit.  These sound like good reasons for making homes more energy efficient, and for installing a diverse range of energy technologies.

To order an EPC for your home to find out what technologies are best for you, contact Find EPC.

Buying a better gas boiler

Gas Boiler

Heating and hot water accounts for well over half of the total energy use in the home, so if you have an old gas boiler, changing to a more efficient model will save you money and give you a higher score on your EPC.

Boiler efficiency

Boiler efficiency is defined as a percentage, with gas boiler installation now restricted by regulations to those with a score of 88% or better. The energy efficiency is rated from A to G, with modern condensing boilers getting an ‘A’ rating.

Boilers more than 15 years old are likely to be inefficient due to hot gases escaping up the flue. Modern condensing boilers have larger heat exchangers that recover more heat.

If your boiler has a plastic flue and a second pipe coming out of the bottom to drain condensate outdoors it is a condensing type. If it does not have one of these, it is worth considering an upgrade.

What is available?

If you have a mains gas supply, a gas boiler is likely to be the cheapest option. There are two main types.  Regular (or conventional) boiler systems heat the water and store it in a cylinder.  Combination (combi) boilers heat the water on demand without the need for a cylinder. A third type, system boilers, are typically used in large houses with a substantial hot water demand.

Regular boiler systems take up quite a lot of space, but provide the highest hot water flow rate. However, they do lose some heat from hot water stored in the cylinder. They are generally a good choice for homes with more than one bathroom and a predictable hot water demand.

Combination boilers are the most popular choice as they are cheaper to install, more compact, and they cannot run out of hot water. They are less efficient than regular boilers when heating small quantities. They are suited to homes with limited space and no existing hot water tank, and those with a less predictable hot water demand. 

A new boiler is a big investment, and the technology can be complex, so check with a qualified installer what would be best for your home.

What if I don’t have gas?

Gas boilers are available that run on liquefied petroleum gas (LPG) from a tank, if there is outdoor space for one.  Oil-fired heating is a popular alternative, though heating oil prices can be volatile. With Government support schemes, low-carbon alternatives such as heat pumps or biomass boilers may present a cheaper option.

How much can I save?

A smaller, cheaper gas boiler may suffice in a well insulated home, so make sure you do that first.  New boiler prices range from approximately £500 to £2,500. Installation costs vary, so getting at least three quotes is recommended.

Your annual savings will depend on how inefficient your old boiler was. As an example, replacing a G-rated gas boiler with an A-rated condensing boiler could save up to £325 in a detached house, or £200 in an average semi-detached house.  An £1,800 gas boiler bought to replace a 60% efficiency boiler will pay for itself in seven and a half years.