Residential CHP systems offer developers an opportunity to take sustainability and reduced emissions into property design. The specialist technology is here to help best manage the impact that residential living has on the environment while reducing waste and improving efficiency. In line with many UK regulations, such as the newly announced Future Homes Standard, there are detailed plans set out to ensure new build homes have a low carbon heating rating and are zero-carbon ready by 2025. With this, developers are at the forefront of this movement to find solutions to suit their next projects while ensuring the quality of life isn’t altered at the same time. In this guide, we’ll cover some of the key points to consider when designing CHP for residential homes.

What Is CHP?

CHP stands for combined heat and power. It is a technology that can simultaneously produce hot water and electricity. It does this by utilising the heat excreted during the fuel-burning process through an electric regeneration process. The system essentially features an electrical generator alongside the equipment used to recover this heat. The generator is generally a prime mover (a gas turbine or reciprocating engine) but can also be a steam turbine depending on the required scale of the system. Larger scale or industrial CHP units may contain a combination of different prime movers to suit the needs. There are 4 main types of CHP systems:

  • Micro-CHP
  • Packaged CHP
  • Custom or bespoke CHP
  • Renewables CHP

The best type for a specific project depends on its individual demands. For example, micro-CHP units are generally used in small to medium-sized domestic properties as well as smaller commercial settings too. Renewable CHP systems, as the name suggests, make use of renewable fuels while custom-built CHP systems best meet the needs of complex or unique environments.

Current Regulations

The UK Government has implemented a number of key legislation, regulations and levies to ensure that property developers design with sustainability and reduced carbon emissions as a key consideration. The main one of these that needs to be considered is Part L of the Building Regulations alongside the newly announced Future Homes Standard. This introduces a primary energy target for new homes in place of a carbon dioxide emissions target. For developers, this takes into account the fact that reducing the carbon output of a property cannot be solely attributed to the decarbonisation of the grid but rather additional design features and adaptations.

Part L of the Building Regulations comes directly from the Government’s Energy White Paper. This is their commitment to improving the energy performance of buildings by limiting heat loss and excessive solar gain. It discusses the conservation of fuel and power when designing properties by providing a building service that is efficient, has efficient controls and is properly commissioned.

Environmental Considerations

Combined heat and power systems utilise a technology that reduces carbon emissions more efficiently than traditional heat and power generation systems. This works to reduce the impact that this required production has on the environment such as air pollution, water pollution and thermal pollution. When building one into the design of a property, it’s important to consider both the initial fuel consumption required during installation as well as the overall savings to the environment expected over time.

Fuel Usage

CHP systems can be powered using traditional fuels, but most commonly are designed to use natural gas. For those seeking the more sustainable and renewable option, biogas is a renewable fuel source created during the breakdown of organic matter including animal waste and food scraps. There are also options for CHP wood chip systems that make use of high-grade fuel with less than 15% moisture content for a low-cost and increased power yield solution. Considerations should be made for the right type of fuel to meet the needs of the expected end client and the budget provided.

Operation and Maintenance Requirements

Packaged CHP systems are designed to require minimal maintenance while allowing the unit to run continuously for extended periods of time. The main consideration here is whether fuel levels can be kept at an optimal grade to support this. If so, the maintenance requirements whittle down to just planned service intervals, recommended at 1 per month and a minimum of 1 planned shutdown annually too.

Most CHP packages are accompanied by monitoring systems that allow you to gain a better understanding of their performance at any given time. Some residential options will have adjustment features, just like normal boilers, allowing you to optimise fuel usage and prioritise efficiency at all times. Considerations into the availability of operational and maintenance support should be taken into account when designing for residential properties. Bringing this to a minimum will ensure the prospect of sustainable heating and power becomes ever-more appealing to a wider audience.

Return on Investment

The initial cost of installing a combined heat and power system can be significant, even on a smaller scale for residential properties. It pays to take this into account alongside the expected return over time too. In properties where the demand for heating and cooling occurs at an extent and over a longer period of time, CHP returns can be significant. The main thing to consider is size. As with traditional boilers, CHP systems need to be sized accurately to allow them to return on the initial investment within a 5 year period. Over the expected lifetime of a unit – somewhere around the region of 15 years – you can expect a significant return.

Energimizer is an industry expert in the design, supply and maintenance of environmentally-friendly combined heat and power systems from existing to new build projects. Alongside our partner, Kw Energie, we produce CHP products designed to optimise on energy production in your home. For more information or to speak to a member of our experienced team, please do get in contact with us here today.