Wednesday 31 July 2013

Micro CHP (micro combined heat and power)

This week I will be reviewing micro CHP systems (also known as cogeneration systems or micro combined heat and power systems) as a cost effective way of providing energy for your home.

Whilst not strictly a renewable energy generation installation, these systems deserve attention as they are highly efficient and can substantially reduce your energy costs.  Industry experts expect micro-CHP systems to replace the humble domestic boiler and become the norm in our homes over the coming years.

How does micro CHP work?
Using gas or LPG as a fuel, micro CHP installations provide both heat and electricity for your home.  Micro CHP installations look just like normal boilers. However, unlike ordinary boilers they will generate electricity at the same time as heating the water.

How much energy will a micro CHP system generate?
The actual amount of electricity generated will depend on how long the installation is set to run.  Typical set-ups will generate up to 1kW of electricity.

What are the advantages of micro CHP?
  • The installations will deliver both heat and electric power.
  • You will be paid for the electricity you generate from the installation under the Government's Feed in Tariff Scheme.
  • Any electricity you generate and do not use can also be sold back to the Grid through the Feed in Tariff Scheme.  
  • Micro CHP systems are straight-forward and non-intrusive to install and do not take up much space (make sure you use an approved installer).

Are there any constraints?
  • Micro CHP installations can be inefficient if they are only being used for short periods.
  • There are a number of technologies on the market, some of which are unproven.

What consents will I need?
The installation of micro CHP is usually considered to be "permitted development", which means that planning permission is not required subject to certain conditions and exclusions.  However, if the installation requires an outside flue, depending on the size and location of the flue, it may require planning permission. Check out the Planning Portal Website for further advice.

Micro CHP systems will have to comply with the Building Regulations.

How much does a micro CHP system cost?
Expect to pay at least £5,000 to £6,000 (including installation costs).  Make sure you use an approved installer.

Are there any grants or other funding support available?
The Green Deal scheme may be able to help you pay for the upfront costs of the installation through Green Deal financing.  The installation costs will then be paid back over time, with interest, through your electricity bill.

Micro CHP systems qualify for 10 years of tariff payments from the Government under the Feed in Tariff (TIF) Scheme.  Find out the current tariff payment rates at www.energysavingtrust.org.uk

Summary
  • If your old boiler is coming to the end of its life, it is worth considering replacing the boiler with a micro-CHP installation.  
  • CHP systems are straight forward and non-intrusive to install (but make sure you use an approved installer)  
  • You can earn money from your CHP installation for any unused electricity that is fed back into the Grid under the Government under the Feed in Tariff (TIF) Scheme.
Further Information
For further information and for details of approved installers check out www.microgenerationcertification.org


David
www.house-saver.co.uk

Wednesday 24 July 2013

Water Source Heat Pumps (Water Source Heating)
In previous weeks I reviewed ground and air source heat pumps as a way to generate energy to heat your home.  Staying on the heat pump theme, this week I review water source heat pumps.  Whilst the least common of the heat pumps, provided that your property fits the bill (and you live close to a suitable water source), water source heat pumps are worth considering.

How do water source heat pumps work?
Water source heat pumps come in 2 types:
  • Open loop systems: where the water is taken from the source (see below*) and then flows around a heat exchanger to generate heat.  The water is then released back to the water source.
  • Closed loop systems: these work like ground source heat pumps, but instead of the pipes extracting heat energy from the ground, the pipes (or panels) are submerged in the water source to extract heat energy from the water.

*Water sources can be in the form of rivers, streams, lakes, large ponds, wells or boreholes.

How much energy will water source heat pump generate?
Most water source heat pump systems will deliver in excess of 4kW of heat energy (and will typically expend 1 kW of electricity to generate this heat energy).

What are the advantages of water source heat pumps?
Water source heat pumps are more efficient than other types of heat pump because the heat transfer rate from water is far higher than the heat transfer rate from the ground or air.  This is especially the case in the winter, when heat energy is most needed.

The installation of water source heat pumps will usually be much less expensive and much less intrusive than the installation of ground source heat pumps (you won't have to dig up your garden).

Water source heat pumps are an ideal option for heating domestic swimming pools.

Are there any constraints?
If the water source dries up then no heat can be created.

Open loop systems, whilst more efficient than closed loop systems, pose a number of challenges.  Open loop systems generally require greater maintenance, especially if the water quality is poor.  The pipes within open loop systems can freeze at very low temperatures. Plus there is the cost and red-tape associated with acquiring the Environment Agency extraction licence to consider (see below).

What consents will I need?
The installation of a water source heat pump is usually considered to be "permitted development", which means that planning permission is not required subject to certain conditions and exclusions.  Check out the Planning Portal Website for further advice.

Water source heat pumps will have to comply with the Building Regulations.

With respect to open loop systems, an Environmental Agency "extraction licence" is usually needed where water is being extracted at any scale.  A discharge consent will also be needed to release the water back into the water source.

Are there any grants or other funding support available?
The Green Deal scheme may be able to help you pay for the upfront costs of the installation through Green Deal financing.  The installation costs will then be paid back over time, with interest,  through your electricity bill.

You may qualify for payments from the Government under their Renewable Heat Incentive scheme.

Summary

  • Given their greater efficiency, water source heat pumps are recommended over ground source heat pumps if you live close to a suitable water source.
  • Water source heat pumps are an ideal option for supplying heated water to domestic swimming pools.
  • You may qualify for payments under the Renewable Heat Incentive scheme.



David
www.house-saver.co.uk

Wednesday 10 July 2013

Air Source Heat Pumps: The cheap to install and easy to maintain heat generator

Air Source Heat Pumps (Air Source Heating)
Last week I reviewed the merits of ground source heat pumps as a way to generate energy to heat your home.  Staying on the heat pump theme, this week I review home air source heat pumps.

In recent years many of our northern European cousins have been installing air source heat pumps in their homes.  Air source heat pumps have become a mature technology that have not yet made it into the mainstream here in the UK.  However, as our energy bills continue to rise, more and more UK households are turning to such technologies to help reduce their heating costs.

How do air source heat pumps work?
Air source heat pumps extract the heat from the outside air. Depending on the system, this heat can then be used to heat radiators, underfloor heating, heating fans or for certain systems to provide hot water.  They basically work like a fridge but in reverse.

There are two main types of air source heat pump system:

  • air to air systems:  these produce warm air which is circulated by fans to heat the home.
  • air to water systems: these provide heat via radiator or underfloor heating.

How much energy will an air source heat pump generate?
Air source heat pumps will deliver in excess of 4kW of heat energy (and will typically expend 1 kW of electricity to generate this heat energy).

What are the advantages of air source heating?

Air source heat pumps can significantly lower your heating bills.  They are relatively easy to install and require little maintenance.

Most manufacturers now offer air conditioners with heat pumps as standard.  Air to air heat pump systems can provide you with both heating in the winter and air conditioning in the summer.  They can also purify the air in your home, great for hay fever and other allergy sufferers.

Remarkably, air source heat pumps work all year round, even when outside temperatures are freezing.

Are there any constraints?
Air source heat pumps require electricity to operate.  

Whilst these systems will work all year round, their performance (efficiency) will dip at lower temperatures.

Air source heat pumps require space around them to allow for the flow of air.

Cheaper and badly fitted heat pumps will suffer from poor performance.

What consents will I need?
The installation of an air source heat pump is usually considered to be "permitted development", which means that planning permission is not required subject to certain conditions and exclusions.  Check out the Planning Portal Website for further advice.

If you live in a Listed Building or a Conservation Area it is recommended that you speak to your local Council before installing.

Air source heat pumps will have to comply with the Building Regulations.

How much does an air source heating system cost?
Expect to pay at least £3,000 for a good system.

Expect a payback period of around 10 years.  (The better heat pump technologies have a 20 - 25 year life span).

Air source heat pumps are cheaper to install compared to other renewable energy systems.  

Are there any grants or other funding support available?
The Green Deal scheme may be able to help you pay for the upfront costs of the installation through Green Deal financing.  The installation costs will then be paid back over time, with interest,  through your electricity bill.

You could get up to £1,300 through the Government's Renewable Heat Premium Payment scheme to help with the cost of installing a heat pump.  Unlike the Green Deal financing, this money does not have to be paid back.  However, to qualify you will need to undertake a Green Deal Assessment before applying.

Your air source heat pump could earn you money under the Government's Renewable Heat Incentive scheme.

Conclusion
  • Air source heat pumps are are relatively cheap and easy to install and maintain.  
  • If you are considering installing an air source heat pump don't scrimp on the quality.  The better systems are much more efficient.  
  • Air source heat pumps work best as part of a modern, integrated heating system.


David
www.house-saver.co.uk

Wednesday 3 July 2013

Ground Source Heating

Ground Source Heat Pumps (or GSHPs)
Last week I reviewed the merits of hydroelectric systems as a way to generate your own energy.  The obvious conclusion reached is that whilst hydroelectric systems are potentially a great option if you have a river or stream running along the bottom of your garden, most of us do not have the benefit of living at such a property.

This week I review the merits of ground source heat pumps. Such systems have the potential to benefit many of the UK's more modern homes, especially if installed at the same time as delivering a home extension or major home renovation.

How do ground source heat pumps work?
Ground source heat pumps use a loop of pipe, which is typically laid under your garden, to obtain heat from the ground.  This heat is turned into hot water in a water cylinder. The hot water is then used to heat your home.

How much energy will a ground source heat pump generate?
The amount of water that can be heated by a ground source heat pump depends on the length of the ground loop. The longer the loop, the greater the amount of heat that can be recovered from the ground.

What are the advantages of ground source heating?
When installed as part of an integrated heating system in a modern home, ground source heating will reduce your heating bills.  

Heat pumps can be used in tandem with underfloor heating and other energy saving technologies to dramatically reduce your energy bills.

Whilst disruptive to install, once in place, ground source heat pumps are efficient and long lasting.

Another benefit of heat pumps is that they double up as cooling devices, and can be used to maintain a comfortable temperature in your home on warm summer days.  

Are there any constraints?
The longer the loop, the greater the amount of heat that can be recovered from the ground, but longer loops need more space to be buried in. However, there is the option to dig downwards where space is limited.

The biggest constraint is often the ability of accessing your garden with the digging equipment. Installation of the pipes involves digging trenches, which can make a mess of your garden.  Ideally, to limit the disruption and to reduce installation costs, ground source heat pumps should be installed when the home is being built, or alongside building a house extension or carrying out a major home renovation.

Heat pumps deliver heat at a lower temperature than a boiler.  So in winter expect to have the heating turned on for most of the time.  If you live in an older property without modern insulation, ground source heating may not deliver the level of heating needed. Ground source heat pumps are not recommended for such properties.

What consents will I need?
The installation of a ground source heat pump is usually considered to be "permitted development", which means that planning permission is not required.  However, if you live in a Listed Building or a Conservation Area it is recommended that you speak to your local Council before installing.

Ground source heat pumps will have to comply with the Building Regulations.

How much does a ground source heating system cost?
Expect to pay around around £10k to £15k for a typical system.

Subject to your property being suitable for a ground source heating system, expect a payback period of around 15 - 20 years.

Is there any grants or other funding support available?
The Green Deal scheme may be able to help you pay for the upfront costs of the installation through Green Deal financing.  The installation costs will then be paid back over time, with interest,  through your electricity bill.

Your ground source heat pump could earn you money under the Government's Renewable Heat Incentive scheme.

Where can I find further information?
For case studies and practical advice on siting ground source heating check out www.gshp.org.uk

Conclusion

  • If you live in a draughty, older property we do not recommend installing a heat pump.  
  • If you have a mature, well tendered garden that you don't want to dig up we do not recommend installing a heat pump.  
  • If you already have a modern, gas fueled condensing boiler we do not recommend installing a heat pump.
  • However, If you are planning a major renovation of you home, we do recommend that you consider installing a heat pump as part of an integrated heating system.



David
www.house-saver.co.uk