External Pellet Stores for Biomass Boiler Installations

Recently we have been installing an increasing number of external pellet stores as part of our biomass boiler prokects, so we thought we would provide you with some more information about these pellet stores and what makes them beneficial to those moving to a renewable form of heating.

How does an external pellet store work?

Containing the wood pellets for a biomass heating system, pellets are transferred to the boiler via a vacuum hose which is hidden underground. An automated system allows the pellets to travel to the boiler, which contains a small store, around two to three times per day depending on the size and requirements of the system.

What are the benefits of an external pellet store?

  • Ideal for properties that do not have adequate space for a store within or near to the boiler house, being built up to 20m away from the boiler
  • Helps to reduce disruption and speed up the installation time
  • Provides easy access for wood pellet deliveries (although pellet trucks can usually park up to 20m away from a pellet store and still deliver pellets to a decent quality due to the length of the pellet delivery hose)

What material is an external pellet store made of?

The external pellet stores that we use are made of galvanised steel and are fully waterproof. Some customers choose to have part or all of its exterior wooden clad to fit in with the surroundings. We can also add custom painted corner capping and finish the exterior cladding to a colour of the customer’s choice.

External Pellet Store

Case study

We recently installed an external wood pellet store as part of a biomass boiler installation that we were undertaking at The Old Mill Centre in Yorkshire, which is a retreat, residential and holiday centre.


Installing a 50kW wood pellet boiler within an outbuilding at the Centre, we identified during the design stages of the project that there wasn’t room for a wood pellet store within the small boiler house. An external pellet store therefore provided an ideal solution, where the store would connect into the system via an underground vacuum hose.

During the installation of the boiler, we erected a concrete base for the pellet store and installed the underground feed which holds the vacuum hose that connects the boiler to the pellet store.

We then installed the external galvanised steel store measuring 4m x 2m x 2m with the capacity to store six tonnes of wood pellet fuel.


The external pellet store was then clad in wood and we tailored the corner capping in a ‘Moorland Green’ to fit in with the style and paintwork of the rest of the property and the surrounding landscape.

To find out more about having a wood pellet biomass boiler installation with Purple Energy, click here.

To find out more about The Old Mill Centre, click here.

RHI Biomass Tariff Degression Announced

Piggy bank energy concept

It was announced last Friday that from 1st January 2015, the small biomass tariff for the non-domestic Renewable Heat Incentive (RHI) will be reduced by 10%.

The 10% reduction will reduce the tier one tariff from 7.6p/kW to 6.8p/kW and the tier two tariff will reduce from 2.0p/kW to 1.8p/kW.

The RHI is a government funded financial incentive programme designed to encourage use of renewable forms of heating. Successful scheme participants are paid for the heat that they generate to heat their properties.

There are two types of RHI:

  • Non-domestic RHI – introduced in November 2011, this provides payments to industry, businesses, public sector organisations and multiple separately rated domestic properties heated by the same system. Eligible technologies include solid biomass, biogas below 200kW, ground and water source heat pumps, geothermal and solar thermal heating systems.
  • Domestic RHI – introduced in April 2014, this provides payments to homeowners, private landlords, social landlords and self-builders. Eligible technologies include biomass boilers, air source heat pumps, ground source heat pumps and solar thermal heating systems.

Uptake of renewable heating systems has increased significantly with the introduction of the RHI. In order to manage the take up of the scheme, the Department of Energy and Climate Change (DECC) assesses every quarter what the current number of accreditations and installations are likely to receive in RHI payments for the next year. This is then compared to the assigned RHI budget for the coming year.

The non-domestic RHI degression announcement by DECC is unexpected but positive, as they had previously announced that the rate was expected to reduce by a minimum of 20%.

This unforeseen change is due to DECC significantly reducing their load factor assumptions, causing a large decline in their forecast expenditure. Therefore, instead of a 20% degression, only a 5% technology degression has been triggered.

However, as the total trigger, which is roughly the RHI budget, was hit, every technology deploying above its individual technology triggers will be degressed 5% in addition to any other degressions. The small biomass tariff will therefore be reduced by 10%. The biomethane tariff also degressed.

The domestic RHI biomass tariff also sees a 10% reduction from 1st January 2015, reducing from 12.2p/kW to 10.98p/kW.

Installations have increased significantly in recent months with expenditure growing at a significantly quicker rate than that expected. The non-domestic RHI has already seen a 5% tariff reduction in July 2014 and a 10% tariff reduction in October 2014. The degression to the domestic RHI tariff is the first since the domestic scheme’s introduction in April 2014.

To read more on the RHI and its changes, please see:


Non-Domestic and Domestic RHI Degression for Small Biomass Expected

Green Savings Piggy Bank

From 1st January 2015, the tariff for approved small biomass applications for the non-domestic Renewable Heat Incentive (RHI) will be reduced by a minimum of 20%.

Non-domestic RHI applicants with biomass installations up to 200kW applying after this time will therefore receive a maximum of 6.1p/kWh on tier one and 1.6p/kWh on tier two.

It is also highly likely that the domestic RHI biomass tariff will be reduced by 10% from 1st January 2015.

Increased uptake of the domestic RHI scheme has meant that throughout the latest two months the estimated future spend in the domestic biomass market increased from £1.84m to £4.03m. The biomass trigger for the reduction is £4.2m.

Although not officially announced until the end of November, the Department of Energy and Climate Change (DECC) released their latest monthly forecast for RHI expenditure on Friday, which provides enough information to guarantee the 20% degression for the non-domestic RHI.

Every quarter DECC assesses what the current number of accreditations and installations are likely to receive in RHI payments for the next year. This is then compared to the assigned RHI budget for the coming year.

Further updates on RHI degression will be provided once details are confirmed at the end of November.

EU Leaders Agree 2030 Energy and Climate Change Framework

Last Friday, the European Council confirmed the 2030 energy and climate change framework. The main points of the framework are:

  • An EU target of at least 40% less on greenhouse gas emissions by 2030
  • A target of at least 27% of renewable energy used at the EU level
  • An energy efficiency increase of at least 27%
  • The completion of the internal energy market by reaching an electricity interconnection target of 15% between EU member states and the pushing forward of important infrastructure projects

These ambitious greenhouse gas targets have been fought hard for by the UK Government and they are continuing to push for reform of the European Union Emissions Trading Scheme (EU ETS). The UK Government believe that they are taking a forward step in the implementation of these renewable energy targets.

Speaking earlier in the year the Secretary of State, Edward Davey, said: “The proposals are a step in the right direction towards an ambitious emissions reduction target for Europe.

“They provide the flexibility to tackle climate change in the most cost-effective way, so that British consumers aren’t paying over the odds to go green.”

However, the Renewable Energy Association (REA), of which Purple Energy are a member of, are disappointed as these targets fall short of what they were hoping for, which was largely due to the Government’s efforts. Though they acknowledge how hard the Government has fought for these targets, they are unhappy with their view towards Member States targets, which the Government have been clear to oppose.

The REA have said that their focus for 2030 will be mainly on the UK Government, so they can urge them to create a clear image for the future purpose of renewable energy in 2030.

As well as this, the European Renewable Energies Federation (EREF), an EU interest and lobby group for independent producers of electricity and fuel from most renewable energy sources, still hold a position supported by the REA. They are now pushing for targets for greenhouse gas savings, energy efficiency and renewable energy.

The World Wildlife Foundation (WWF) have similar feelings towards the UK Government. Leo Hickman, Chief Adviser for Climate Change at the WWF-UK said: “Whilst we recognise that the UK Government fought hard to secure as high an emissions reduction target as was deemed politically possible, scientists are clear that this package is insufficient to avoid dangerous climate change.”

The WWF hope that the EU review its target and “deliver targets that will drive a rapid and just transition out of fossil fuels and into renewables and energy efficiency.”

It is clear that progress is being made towards improved energy and climate change targets but the difference in opinion as to whether the 2030 targets are enough highlight the potential for increased targets within this time frame.

To read the full report published by the European Council, click here.

The Domestic Renewable Heat Incentive Tariff Levels and Additional Information


As Spring 2014 draws closer, we are receiving more and more interest from customers hearing about the Domestic Renewable Heat Incentive (RHI).

The Department of Energy and Climate Change (DECC) announced the tariffs for the scheme earlier this year, stating that its “aim to introduce these changes by Spring 2014 remains unchanged.”

The Domestic RHI scheme will pay renewable technology owners on a quarterly basis for seven years at tariffs set at a level that reflects the expected cost of renewable heat generation over 20 years:

  • Biomass: 12.2p/kWh
  • Ground source heat pumps: 18.8p/kWh
  • Air source heat pumps: 7.3p/kWh
  • Solar Thermal: 19.2p/kWh

On top of this there will also be an extra incentive for applicants who install metering and monitoring service packages of:

  • Heat Pumps: £230 per year
  • Biomass: £200 per year

The financial support will cover single domestic dwellings and will be open to:

  • Owner-Occupiers
  • Private Landlords
  • Registered Providers of Social Housing
  • Third Party owners of heating systems
  • Self Builders

Anyone in these groups may apply for the RHI provided they meet all the criteria and so long as the technology in question was installed since 15th July 2009. This means that interested customer do not need to wait until the scheme is introduced before having a renewable heating installation.

Other eligibility requirements for the scheme include:

To read the consultation document on the proposals for a Domestic Renewable Heat Incentive, click here.

Updates to the Non-Domestic Renewable Heat Incentive (RHI)

RHI fact sheet photo

With the introduction of a new scheme for householders, and changes to the current non-domestic payments, the Renewable Heat Incentive can get a little overwhelming. Hopefully our blog posts can help break things down a little, with this post covering the recent changes to the non-domestic RHI.

Regulatory changes to the non-domestic RHI came into play on 24th September 2013 in the hope that the RHI could provide a much simpler means of testing for eligibility.

The two main changes are:

1. The simplification of metering requirements:

  • OFGEM now require only the minimum number of meters in order to calculate RHI payments
  • Heat loss from external pipe work will now be disregarded in certain circumstances
  • Applicants who can prove that it is either physically or financially burdensome to install a heat meter, will instead be allowed to submit a heat loss calculation instead of installing additional meters.

 2. Increased air quality requirements for biomass boilers:

  • Applicants with biomass boilers must now meet any Air Quality requirements
  • This means that to qualify, an RHI emission certificate or a valid environmental permit must be submitted alongside the application
  • The installer of the system should be able to provide the RHI emission certificate for the system

Further changes and improvements to the non-domestic scheme include:

  • Allowing heat to be used for processes other than in a building in certain circumstances
  • Allowing accredited installations to be relocated, as long as the installation meets all necessary requirements at its new location
  • Allowing installations that were used by an installer to gain their Microgeneration Certification Scheme (MCS) accreditation to be eligible for the RHI

How to improve your Energy Performance Certificate (EPC) and increase the value of your property

Research released by the Department of Energy and Climate Change (DECC) has shown that the value of a property could increase by 14% on average through improving its Energy Performance Certificate (EPC).

The purpose of an EPC is to establish the energy efficiency of a building and its environmental impact.

To achieve an improved EPC, property owners can do the following:

  • Change to renewable energy for heating, through for example, installing a biomass boiler
  • Use renewable energy for electricity, such as by installing solar PV panels
  • Use low energy light bulbs
  • Install loft insulation
  • Install double glazing
  • Insulate hot water cylinders
  • Have cavity wall insulation added to the property
  • Use heating controls including timers and thermostats to reduce unnecessary heating and electricity use

The study by DECC shows that region affects the size of the increase in property value. For example, in the West Midlands, improving EPC from a D rating to a B rating could increase property value by £16,882; in the North West, improving from G to E could bring an increase of £23,155.

To find out more about how you could make use of renewable technologies, visit www.purpleenergy.co.uk or call us on 01782 630077.

It should be noted that many other factors affect EPC rating and an increase in property value is not guaranteed.

Information about the report and figures used are taken from https://www.gov.uk/government/news/energy-saving-measures-boost-house-prices .