How to Get the most from Your Renewable Energy Sources: Sunamp Heat Batteries
As specialists in designing extremely energy-efficient homes, at ACA we are often on the lookout for exciting new forms of energy-saving technology. Right on our doorstep in East Lothian, Sunamp design and produce non-toxic, compact Heat Batteries that can store heat from a variety of applications – including many renewable and low-carbon technologies.
We’ve been quite intrigued by Sunamp as it has developed; it has emerged as a sensible option for Self Builders who want to get the most from their renewables. The Heat Batteries deliver heat and hot water on demand, and work with the likes of Photovoltaic (PV) panels. Earlier this year we put our questions to Sunamp’s Joan Pisanek, to find out a little bit more, and here’s what she had to tell us about the Sunamp Heat Batteries:
Can you talk us through how the Sunamp Heat Batteries work?
Based on the same principle as hand warmers, Sunamp Heat Batteries contain inorganic, non-toxic, salt based Phase Change Materials (PCM) which absorb and release thermal energy during the process of melting and freezing. When a PCM freezes, it releases a large amount of energy in the form of latent heat at a relatively constant temperature.
What are the biggest benefits of installing a Sunamp system in a Self Build home?
Sunamp Heat Batteries are easy to install, modular, flexible and space saving. They deliver high flow-rate hot water on demand, as well as dramatic efficiency gains and cost savings.
Not only that, the Sunamp system beats hot water tanks and electric batteries for size, power and price. The bespoke design can be tailored to meet exact requirements – and it is also easy to add additional storage to a system in the future if required.
Are there any other systems like Sunamp, or is it unique?
There are other phase change materials out there such as Palm Oil, but we haven’t seen any that work. We’ve spent many years developing this, working with some of the best experts in the field.
Can the Sunamp Heat Batteries be installed easily retrospectively, or is it best to plan its inclusion at design stage with architects?
Whilst it’s best to be able to plan for the system at design stage, it’s not difficult to retrofit the storage, as it can be used with a large number of heat sources.
We’ve completed a number of retrofit projects in social housing where we’ve changed the equipment in a cupboard without changing anything in the rest of the property. It is possible to include additional storage at the outset or add to the system at a later date.
Does the Sunamp system require regular maintenance, and how long will the battery last?
It’s a sealed system and there’s really not a lot that can go wrong, although we recommend an annual check just to ensure that filters are clear and electrolytic scale inhibitors, where required, are functioning.
The red cells are linked but not interdependent on each other, so in the unlikely event that a cell malfunctions the system will still work, with a little less capacity, until the cell can be replaced.
It has a very long life and we offer a 10 year warranty on the cells. Accelerated lifecycle testing is already over 14,000 cycles. Each cycle includes a charge and discharge which represents 35 years with no degradation.
What does it cost for a Sunamp system, and do you supply PV panels too?
The prices range from £1,700 for a 5kWh system, to £7,500 for a 40kWh store (excluding VAT and Install). We work with our partner Edison Energy, based in Glasgow, to provide a complete package including design and installation.
What are the typical financial paybacks over, say, a 20 year period?
The smallest Sunamp heat battery, SunampPV, will pay back in under ten years if installed with an existing SolarPV system. Larger systems will vary depending on what it’s being integrated with.
For example, we installed a large battery system with an air source heat pump in an all gas, 275sqM, 5 bedroom home in Edinburgh; saving around £1,200 per annum in fuel costs. The full install cost was £17,500 so payback was less than 15 years.
Do they require specialist servicing?
No, and there are no installation requirements such as FGAS or MCS.
What is the desired heating system set-up (i.e. Airsource heat pumps, UFH, etc.)?
Sunamp Heat Batteries can work with any renewable system. It was designed to work with any heat source, so it will also work with Ground or Water Source heat pump, Solar thermal, Wind turbine or BioMass.
Most of our experience has been with SolarPV, Air Source Heat Pump and Grid Electricity, often with the three working together.
SunampPV works very well with SolarPV, and a gas combi, or as an electric water heater.
SunampStack works incredibly well with an ASHP. Our material melts at 58°C so we need a temperature of 60°C-62°C to melt it and for that reason we’ve chosen to work with the Daikin Altherma High temperature heat pump on a number of installations. The ASHP operates on the off peak tariff and the SunampStack stores the thermal energy to provide hot water and heating at any time.
It can feed directly into a wet radiator system, or be blended down for UFH, as well as supplying domestic hot water for baths and showers from the same battery. It’s very versatile.
New build properties typically need low levels of heat and lots of hot water, whereas older properties need more heat. We can configure the battery to fit the need.
Where do you see Sunamp in 5 years?
We’d like to see Sunamp become a Global name, and we are really excited about the future. There are just so many different ways to use the technology and heat stores; currently, systems for cars, buses and boats are all being developed.
Are there any other technologies that you are working on that you could tell our readers about?
We have started a project to palletise/containerise heat stores, and then move it to another location. This development will enable us to make use of waste heat and energy from stranded assets such as constrained wind turbines.
You can find more articles about other renewables below: