Ground Source Heat Pump

ground source heat pump

Ground Source Heat Pumps – Their Cost, Their Installation and Their Efficiency

Heating accounts for a significant portion of a household’s energy demand and a ground source heat pump system can provide a cost-effective and sustainable way to warm a home. The pump uses a small amount of electricity to transfer naturally occurring heat from the adjacent ground into the house.  As the temperature just a couple of metres below the surface remains more or less constant at 11°C to 12°C, it is possible to design a very efficient heat transfer system.

How does it work?

A sealed loop of fluid-filled pipe is buried in the garden or driveway. The length required depends on the size of the home and the amount of heat required. An average system for a family dwelling will typically require pipework up to 100m long.  Vertically drilled boreholes and deeper pipes can be used in more confined spaces. Once installed, the ground is restored to its original condition and the system becomes invisible.

The ground source heat pump circulates water and antifreeze around this loop. The fluid absorbs heat from the ground before it passes through a heat exchanger.  Energy is then transferred to the heating and hot water circuits of the home. The cooled fluid flows back into the ground loop in a continuous process for as long as the heating is required. Some systems can also be designed to meet cooling needs in summer.

While there are some minor residual energy and carbon costs, hooking the pump up to a home renewable technology such as a solar panel can increase its sustainability credentials even further.

What properties are suitable?

Ground source heat pump systems are not suited to every type of property. In general, they work most efficiently in well insulated homes with a relatively even and low heat demand. They produce heat at a lower temperature than more conventional central heating so a larger area is required for heat distribution. Underfloor heating is the ideal partner, though large heat pump system radiators are available. The system also requires sufficient outside space for installation. While minimal on-going maintenance is required, there can be considerable disruption during installation, and the system tends to be more attractive for new-build or as part of a wider home improvement project.

A typical domestic ground source pump is the size of a large upright fridge freezer. To save indoor space they can be installed in an outbuilding or basement.  They just need to be as close as possible to the end of the ground loop pipe. With a typical noise level of a little over 40dB at one metre away, they are as quiet as a fridge.  That’s considerably quieter than a typical gas or oil central heating boiler.

What do they cost and how much will I save?

Costs and savings will be dependant on the size of the pump, the length and depth of loop installation, the energy efficiency of the property, the sort of heating system that is being replaced and whether any additional work is required on the wider home heating system.  A typical domestic installation costs £12,000 to £15,000, with annual running costs of £600 to £700. At current prices, the payback from a ground source heat pumps is unlikely to represent an attractive alternative to an established mains gas central heating system. However, installers claim energy savings of nearly £1,500 annually for a typical four-bedroom house when compared with standard electric heating, or around £600 when compared to oil-fired central heating. That represents a saving of nearly 5,000kg of CO2 emissions each year.  Government Renewable Heat Incentive grants are currently available for installation.

Their installation will also greatly improve your energy efficiency score on your EPC.

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If you’d like to book an EPC for your home, simply contact us by phone or email, or fill in our contact form.

 

Can Switching Save Energy as well as Money?

EPC - Switching

Back in 2006, householders had only ten energy suppliers to choose from, and most bought from one of the ‘big six’, British Gas, EDF Energy, E.ON, npower, ScottishPower or SSE. Today, domestic customers have a choice of more than 40 suppliers, but the big six still supply well over 90% of British households with gas and electricity.

Despite advertising campaigns by the new entrants and price comparison websites, many people still believe that switching supplier is a daunting process. In reality, market reforms by Ofgem to create a more level playing field for small suppliers have made the process quite straightforward.

Customers can research and handle the changeover themselves with the assistance of their newly chosen supplier, or they can use one of Ofgem’s accredited energy comparison websites such as uSwitch, Moneysupermarket or Simply Switch. The full list is available here.

Ofgem suggests that switching can bring annual savings of around £300, according to its latest research. Of course, householders may also want to take the quality of customer service provided by the suppliers into account when choosing, and Ofgem can also help with customer complaint performance results (here).

Smaller suppliers are gradually gaining a presence, making the market more competitive. At the moment, the majority of them have fewer than 250,000 customers, but names like Ecotricity, OVO Energy, First Utility, Bulb, Octopus Energy, Robin Hood Energy, First Utility, Good Energy and LoC02 are becoming more well known. Many of them provide 100% of their electricity from renewable sources, an important consideration for many consumers choosing a new supplier.

Some people find that gathering information to make a decision about potentially switching supplier encourages them to record their electricity use more carefully, identifying trends and focusing on the number of units used as well as the costs. In so doing they become more aware of their usage and this leads to savings in consumption as well as unit costs, a double benefit of switching.

While a series of meter readings will be useful to get a more accurate report, all you actually need to make energy supplier comparisons is your postcode and a recent energy bill (or information about your household and lifestyle). It only takes about ten minutes. Ideally, use an Ofgem Confidence Code accredited comparison site, and be aware that you may need to opt in to seeing the data about suppliers that the website does not directly deal with.

Enter the information that is requested, review the results, and pick a new plan. It is as simple as that. Some options will be variable rates, some will be fixed over a specified term, and some will have early exit fees. The choice is yours.

The switchover will take around three weeks, and there will never be an interruption to supply. The same cabling and meter will be used. The only noticeable changes will be the company name on the bills, and the reduced amount on the bottom line!

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.

Smart Meters and Other Smart ways to Control your Energy Use

smart meters

It seems that everything around the house is becoming smart, including heating controls and smart meters, but will these save energy and money and make your home more sustainable?  

Smart heating controls

One way of tackling your energy use is to install a smart thermostat on your boiler. This allows you to control the heating from just about anywhere by using an app on your smartphone or tablet. You can also control the heating in each room individually by using smart radiator valves.

Technology is heading towards smart boilers and integrated heating systems that will incorporate these features and more besides, including the ability to detect faults and alert you to them, as well as allowing an engineer to diagnose and deal with the problem remotely.

Smart meters

Once you have smartened up your heating, you will want to know what savings you are making and a smart meter will help you to do just that. They use built-in wireless technology to automatically send regular gas and electricity usage data to your supplier.  There will be no more visits to read your meter and, theoretically at least, no more inflated or inaccurate estimated readings.

They come with wirelessly connected monitors that show how much energy you are using and translate that into real money.  By switching things on and off, you’ll be able to see where you are using the most energy and the effect of using that app to turn down the boiler! 

Of course the smart meter itself will not save money, but by drawing attention to your rate of energy use the hope is that it will change your behaviour, perhaps persuading you to do a cooler wash or to switch off a few lights when you can actually see the difference that this makes. You will also know what to expect in your next bill, reducing the risk of a nasty surprise.

The Government wants us all to have smart meters by 2020 as part of its push towards low-carbon targets and by September 2017, 8.6 million had been installed.  The programme is being rolled out by the energy suppliers, some more quickly than others, at a cost of  £11.3 billion, with the Government estimating net savings to the country of £7.3 billion. There is no direct outlay for the householder because the costs are being recouped over time through energy bills in general. 

On the downside, smart meters have had some bad press, with fears that the technology is already obsolete, customers experiencing connectivity problems and other difficulties when switching supplier.

So what will I save?

Smart thermostats cost approximately £300 plus installation and smart radiator valves are around £50 each. One supplier claims that they pay for themselves in the first year, but that will depend on the unpredictability of your comings and goings and on your energy usage.

The Government believes that smart meters will encourage energy efficiency and save an average household some £26 per year on their gas and electricity,  approximately 2% of their total bill.