Considering Using Renewables: What Are the Install Cost Implications

Using feedback from Clients and Contractors we wanted to provide an analysis[and costs where we are provided with them] to assist Cleints in making decisions about whether to use renewables. When reviewing renewables it is not just the cost of the kit that needs to be considered, but the knock on plus and minus costs. The overall benefit should also be factored into the equation. Information on this page is subjetive and would need to be reviewed per project, current technical data, current costs and any current government incentives.

Ground Source Heat Pump

For a recent 3 Bedroom Farmhouse [full refurb late 2022--Feb 2024]
Total refurbisment project GIA 180m2 - 130m2 at GF and 50m2 at FF.

13kW Ground Source Heat Pump, 10kW required with 20% buffer.

Installation included water storage tank, secondary hot water buffer tank, install sundries, 5 x 50m slinky pipework in ground trenches [4 trenches plus 1 feeder trench]

The installation feeds wet underfloor heating to all of the ground floor and upper floor rooms, and hot water supply to a bathroom and shower room, utiltiy and kitchen.

Cost 2022: £18k, taking into accoiunt a £6k Government grant claimable once the installation is complete and operational, reduced net install cost to £12k

Kensa, Nuheat, Vaillant provide similar quotes.

GS Install Visits 2no, one to lay pipes/slinkies in the trench and 1 to install pump, tanks and finalise installation.

Add Trenches cost approx £3-4k to dig - man and machine hire at £350 a day , trenches took 4 days to dig and 4 days to fill. Digger was used for other trenching during this time. 4 x 10m long generating trenches and 1 x 10m long trench returning slinkies to a manifold, then into the main house pump and storage tank.

Add Fill cost of sand to cover the the first part of pipes in trench, before earth was filled and allowed to settle. Settling of earth took one year..

Add: Excess earth was redistributed on the field. So there would be additional cost of earth removal off site to add, if you did not have capacity to distribute some displaced earth on site.

Add: Power supply was upgraded to 3 phase to serve the GS heat pump. Domestic properties normally have single phase supply.

Technical: This type of system is suitable for properties with land. The systems are up to 400% efficient. The system extracts free heat from the ground, and uses this to provide heating and hot water. A GSHP helps to produce your carbon footprint and can lower your energy bills. Effectively you are purchasing the kit at todays costs to provide you with energy for free for future use.

To review the cost of payback you should factor in your annual bill now divided by the Install quote to determine how many years you will be paying forward your energy bills. Plus potential increases in future energy costs that you will save.

Operation: A GSHP uses a network of pipes, either in ground trench loops or boreholes, that are buried in the ground. These are filled with refrigerant that gently extract the heat from the ground, [at approx 1m in depth] before passing it through a compressor in the GSHP to increase its temperature. This higher grade heat energy is used for heating and hot water provision.

A well designed GSHP will be 4 x more efficient than a gas boiler, deliver low running costs. Whilst still benefitting from the Boiler Upgrade scheme [2023]. or another Renewable incentive scheme the Government may introduce.

Pros:-

• Incredibly efficient, a GSHP transferes approx 4 times more energy into your property as heat than it uses to extract it from the ground.
• MCS approved for the Boiler upgrade scheme
• Well suited to properties with larger plots
• Ground loop or bore hole installation options
• Virtually silent options

Cons:-

• Takes a while to heat up, so you need to factor in time lag, and would need an alternative heat source in one room for those occassional colder nights
• Electric required to drive the heat pump, means cost or additional solar panels to generate the energy

Bore holes: Where sites have less land, Bore holes can be used to put the pipes into the Ground.

Piled Foundations: On some sites the Pipes can be connected to a coil and embedded in trenches drilled for piled foundations

Air Source Heat Pump

A heat pump extracts heat energy from the air, even when it is cold outside, and uses this to warm your property.

A well designed heat pump system transfers around three to four times more energy into a property as heat than it uses to extract it. As a result heat pumps are relatively efficient.

Little Outdoor space is required to site the pump. Unobstructed space is needed in front of the heat pump.

Dependant on the location and siting some can be installed under PD rights [these need to be reviewed for your particular site]. installation needs to meet MCS020 standards.

Note that with an Heat Pump the min piping to radiators needs to be 15mm copper , therefore air source heat pumps could not be installed where the dwelling has exisitng small bore copper pipe, unless you factor in replacement of all the copper pipe.

Costs: Cost example for a 250m2 property £11,500 [2023]

Grants: Air source Heat pumps qualify for the Boiler Upgrade Scheme £5,000 grant [2023], the Grant cannot be claimed until install is complete and operational.

Government Incentives

in Spring 2022 the Government introduced the Boiler upgrade Scheme to encourage households in England and Wales to switch to low-carbon heating systems in place if gas or oil fired heating. The scheme offers up to £5k to assist with the upfront costs of upgrading to air source and up to £6k for Ground source

Solar Panels- In Tile

For a 3 Bedroom Farmhouse - to serve a GIA 180m2

Install Mar 2023 of 12 x 400w Panels were installed on a South facing roof. plus 2 x 2.5kw Batteries to store generated power, plus Inverters.

Installer: Underwood Electrical

Cost 2023: £11k, batteries included in this were £1600 each, panels therefore £7.8k [£650 each]

Add: Cost of scaffold for access to the roof

Note: The trays for the solar panels with in tile type are fixed directly to the tiling battens, and are flashed around at perimeter tile junctions. So you need to factor in the saving in roof tiles that are not required under this solar panel type, which is so much neater, and sits flush with the roof tiles

Updates: on Usage to follow

 

Solar Panels - On Roof

For an existing 4 Bedroom dwelling with 2 shower rooms and 2 reception rooms - to serve a GIA ??m2

Install Apr 2024 of 13 x 400w Panels were installed. 8no on a South facing roof and 5no on North facing [99 yr lifetime guarantee]
Plus Inverters.[99 yr lifetime guarantee]
Plus 1 x 5.9kw Battery [10 Yr guarantee]
Battery storage: as close to max 6kW allowed domestic export to the grid, to store generated power.

Panels calcuated to generate 4,400kw/yr, Customer current consumption 3,100kw/yr
7% return of investment yr 1, Install Cost covered by Yr 10.

Installer: Project Solar

Cost Install April 2024: £16,800k, less £2,997 install incentive grant = £13,800 inc scaffold on two elevations

Note: The panels are fixed on black rails tight to the tiles, unlike some panels. Roof tiles are retained.

Updates on Usage: to follow

• Panels on South roof generate between 0.9 to 2.4kW of energy per panel [dependant on cloud cover]
• Panels on North roof generate between 0.7 to 1.7kW of energy per panel, for the same time periods [dependant on cloud cover]

First year Power generation Supplier Octopus, Feed in Surplus Energy forced between 4 to 7pm, Set to Self Use then Feed In

• Feed in tarrif - min 0.145p per unit, max 0.240p per unit
• Jan - 0kW, 234kW Use, Import £85.80, Standing £?, Export £0, Gas £496
• Feb - 0kW, 214kW Use, Import £85.80, Standing £?, Export £0, Gas £496
• Mar - 0kW, 231kW Use, Import £77.22, Standing £?, Export £0, Gas £172
• Apr - 230kW, 108kW Use, Import £11.14, Standing £7,28, Export £0, Gas £32, Solar Installed half way through month
• May - 607kW, 285kW Self Use, 54%, Import Cost £4.86, Import Standing £18.80, Export 322kW Paid back £27.30
• June - 614kW, 271kW Self Use, 45%, Import Cost £6.80, Import Standing £18.20, Export 374kW Paid back £79.29
• Feed in tarrif reduced to min 0.145p per unit, max 0.218p per unit from 1 July
• Jul - 461kW, 188kW Self Use, 41%, Import Cost £12.80, Import Standing £18.80, Export 273kW Paid back £67.15
• Aug -
• Sept -
• Oct -
• Nov -
• Dec -
• Jan -
• Feb -
• Mar -
• Apr -
• Total First Yr May 2024 to Apr 2025 - Pending

Gas Boiler v Air Source v Electric Boiler

In the first instance if you are replacing a Gas Boiler you should consider purchasing one that is A+ rated and allows for future conversion to another gas source, plus a solar panel feed in loop.

If you are thinking about replacing a boiler, then first compare the cost of an Air Source heat pump, or Electric Boiler. Note that with an Heat Pump the min piping to radiators needs to be 15mm copper , therefore air source heat pumps could not be installed where the dwelling has existing small bore copper pipe, unless you factor in replacement of all the copper pipe.

Electric Boiler

One option for installation of a Heat generating device would be Installation of an Electric Boiler. This would be fed by Electricity generated by Solar panels, and would in turn feed either under floor heating or radiators, and hot water requirements. Use an Electric boiler with a solar feed.

Costs: Awaited from project on site 2023

Requirements: Package Water storage tank to store water heated by the Boiler.

Effect on Bills

With a System that uses only electricity and no gas, then Bills will be reduced as there will be no Standaing Charges for Gas meters

Usage charges will be reduced where Electricity is generated using Solar power or other means and used at point of source during the day, and from battery storage in the evening, thereby reducing consumption charges for energy bought in from the national grid.

Any surplus solar energy generated can be sold back to the national grid to generate a small income. Subject to your usage, and the surplus power generated..

Other Energy Saving Devices
Radiator Valves

Installation of digital radiator valves in leiu of standard radiator valves allows individual room rads to be programmed to different temperatures during the day. these can be programmed to lower temperatures when rooms are not in use, to suit occupancy and users.

This type of system also requires a bridge to be connected to your WiFi router and the valves linked with the bridge. This allows the rad valves to be controlled via an app.

Nest or Hive Heating Control

Installation of a digital heating control, provides timed thermostatic control of the dwelling, telling the boiler what temperature the house [or commercial property] needs to be at. The device can be programmed to different temperatures at different times of the day. This allows manual control of the temperature as well as remote control via the app, even when away from the home.

When installing digital radiator valves, it is important to set the Hive/Nest to the max temperature that a radiator valve is to reach, allowing the radiator valves to control individual rooms. However, the Nest does allow occpants to manually adjust the temperature down when leaving unplanned.

Ensure the Nest is not located in the warmest room, as the temperature would be taken from that room

Use of digital devices such as those described above has cost benefits to energy usage.