Solar heating panels are the grandfather of solar technology
Learn about hot water from traditional solar heating panels. Also known as flat plate solar panels, these heat water and reduce immersion coil usage.
Your home's heating system will operate more efficiently while extending boiler life. From March to October, your boiler won't need to be used at all. Solar heating panels heat due to the sun's short-wave radiation converting to long-wave on impact.
In a nutshell:
Not suitable for combi-boilers.
Temperatures from 40-80° Celcius.
Passive heat generation
Before the advent of photovoltaics, solar heating was King. A common misconception is they only work on hot sunny days. This perception is untrue, although they do operate at peak temperatures on such days.
A popular solar technology before the advent of PV with heat converters.
Questions about solar heating panels
Most homes are suitable. If you have a S/SE/SW or east/west facing roof space, then great.Your internal plumbing needs to be checked for compatibility too.
A solar heating system heats up due to the sun's short-wave radiation output converting to long-wave radiation. This process creates heat.
The variable speed controller circulates based on temperatures within the panel.
The pump circulates a Glycol solution through the hot collector and backs down through a heat exchanger.
The system automatically shuts down when not in use, or when the collector temperature is lower than the cylinder.
Do solar heating panels work in the UK climate?
The UK receives 60% of the sun's radiation compared with the equator. Each square metre of the UK receives between 900 to 1,300 kWh annually. All can be captured and diverted into your hot water tank with evacuated tubes.
What about Combi boilers?
Combi boilers aren't possible in most cases. We would need to re-install a hot water tank. Most homes with Combi's won't have the space to install a hot water tank.
Can I install solar heating myself?
In most cases no. However, if you're Part P electrical accredited, then it may be possible to install in a DIY capacity. All solar heating panel installations must be carried out and commissioned by an accredited MCS installer only.
Is there a danger that it could get too hot?
The system may never rise above 85° Celcius.
Why update my hot water tank?
Older 'copper' hot water tanks run exceptionally inefficiently, especially after many years of use. Limescale will reduce performance even further. When installing a solar heating system, it's essential to establish a modern more efficient tank to get the most out of your system.
Will it contribute to my central heating?
We would need to check your management system is suitable. In most cases, solar heating can contribute to your central heating via underfloor heating.
How long will it take to install?
Only a few hours in most cases.
Do I require planning permission?
Listed buildings, conservation area homes, national parks may require permission. Please consult with your local planning officer.
Does solar heating work on cloudy days?
This question depends on the density of the cloud. In average cloud density, solar panels use passive energy. With dense cloud cover, probably not.
Can you upgrade my hot-water tank?
Does your tank has an unused twin coil? In most cases, we update the hot water tank to allow a secondary connection to the evacuated tube system.
How long do solar heating panels last?
A system will easily last twenty-five years.
DIY solar heating panels kits
These first-generation solar heating panels are designed to sit upon or integrate into your existing roof. A-frames are available for ground-mounted installation.
System requirements:
Tank size: 220-300 Litres.
2 x Solar heating panels. 1 x Roof fitting kit.* 1 x 25 Litre expansion vessel. 1 x Expansion installation kit. 1 x Controller & pump station. 1 x 10 Litres fluid. Connectors. Twin-coiled tank.
Specifications:
Length: 2206mm x Width: 1205mm x Height: 100mm. Weight per panel: 55 kg. Aperture Area: 0.995 m2 Efficiency: 95%. Fluid Capacity: 550m.
When working with heights, electrics, and plumbing, always use the correct safety equipment or work alongside an accredited professional.
Low-E (low iron) glass prevents heat loss. Low-iron glass has less reflective and increased absorbing properties.
Installation guide.
For every 100-180 Litre tank size, you will need two m2 arrays or three m2 for 180-300 Litre.
On-Roof installations:
This installation sits above the roof covering anchors or fixing points that secure underneath the slate/tile roof onto the roof battens.
In-Roof installations:
This installation sits directly onto the roof batons with the tiles/slates sitting around the panel. Flashing weatherproof the edges.
Self-installing solar heating panels
Health and safety should be a priority when self-installing solar heating panels.
1. Scaffolding will be necessary up to the level of the guttering. This equipment will give you a safe working platform. Use additional roof ladders to prevent damage to the roof covering. Making measurements from the inside of the roof space/loft may be helpful.
When deciding where to locate the pump station, choose the shortest route for your pipework to the hot water tank.
2. The roof anchors get fixed into the underneath roof batons. You can remove a tile or slate to gain access. Measuring diagonally from corner to corner will help square up the anchors, ready for the aluminum mainframe to be fixed.
The best part of this installation is attaching the solar panels to the roof. Some styles of evacuated tube collectors allow you to piece together the array.
Please note - Ready-assembled collectors will need to be hoisted up to the scaffolding using a roofers pulley system. Some self-installers work alongside a roofing company for this stage of the installation.
An inlet and outlet hole for the pipes can be drilled through the tile/slate and resealed using roof-grade silicone. Make sure any exposed pipework is insulated by an 'Armoflex sheaf' up to the headers inlet and outlet ports.
3. Routing your pipework down towards the pump station can be done with professional 'ready insulated' pipe lengths containing the temperature sensor wire or traditional copper pipe. If the latter, then we recommend connecting with 'compression' joints. Connect the pump station to the correct hot and cold feed connections.
The Expansion Vessel gets installed next to the pump station so, allow for this area. Typical locations for these components are in the loft space, basement, or within the airing cupboard.
4. Some solar heating installations may require an upgraded hot water tank. Unvented or pressurised cylinders are typical, but a 'G3' plumbers accreditation is necessary - however, a traditional vented tank installed with a secondary solar coil is fine.
5. Now decide where to locate The Controller. If you're installing it in the bathroom, then a Part P qualification is required. Situated outside the bathroom area is more common.
Routing the Temperature Sensors from the controller to the tank and header can follow the route of the pipework in most cases.
6. Pressurising the system with the Glycol fluid can be done with a plumber's pump unit. Flushing the system out of all air bubbles is essential, and the pressure of three bars is standard. The final operation is to set up the Management Controller and test the temperature sensors are reporting accurate readings.
Check pipework and connections.
7. Enjoy a cup of tea. You've joined a growing army of people taking advantage of solar technology today.