Surface Water Source Heat Pumps
Code of Practice
Kingston Upon Thames
Mike Spenser-Morris, Zero Carbon Partnership, introduces the launch:
I would like to thank everyone for coming to the launch of the new Code of Practice – a document that will act as a guide for anyone whom intends to install a Surface Water Source heat pump system that would harness the enormous, constantly replenished supply of solar energy that is naturally stored in each and every body of open water.
The document has taken a great deal of time and effort to put together and along with my fellow members of the steering committee I would like to publically thank Jen Billings and Nic Wincott who were the principal authors of the Code and Phil Jones who, as CIBSE's chairman of that committee guided the whole process. I would also like to thank DECC for commissioning the document, and though he is not here, the former Secretary of State, Sir Edward Davey, whose support for the technology was key to moving it forward, and Amber Rudd for her on-going support.
I assume that everyone here today has an interest in the system, whether as a private or public sector adopter, equipment supplier, contractor or consultant. You will all find the document of great assistance in all aspects of the design and installation process. It would certainly have been a very useful tool for me and my team during the time we spent carrying out our installation here at Kingston Heights – but unfortunately we had to find out for ourselves a great deal of the information that is now available to you in the Code of Practice.
Also available is some practical advice or guidance from me and the members of The Zero Carbon Partnership team who have been responsible for the Kingston Heights installation, many of whom are present today.
The system we installed serves the development of 137 apartments and the 145 bedroom Doubletree by Hilton hotel and conference centre that will be opening this autumn. The system is able to produce up to 2.3 MW of thermal energy via the plant room just next door which, as you will shortly see, is very compact for the scale of development it is serving.
By the way, the external appearance of the plant room looks a little stark at the moment but it will shortly be surrounded by a beautiful new restaurant that will shortly cover the entire barge dock.
I am sure you will today hear much from other speakers about the technical aspects of heat pumps, but I would just like to give you some background about my involvement with the system, and the reason why, I believe, everyone throughout the UK should, wherever possible, wish to see open water heat pump systems utilised as the thermal energy system of choice.
So let me explain how the system came to be installed here.
The requirement to have a district heating system, as opposed to the individual gas boilers that would have ordinarily been my company's choice, came from the sustainable energy team at the Greater London Authority as part of my company's planning application process back in 2006. The GLA had further asked for the system to be fed by gas-fired CHP and wood pellet fired boilers, and this met Kingston Council's 10% Renewable Energy requirement in the consent that was subsequently granted.
Unfortunately the development process was delayed as the result of the need first for a public inquiry and then the 2008 recession, so it was 2010 before we were applying to the local authority for the discharge of the consent's Renewable Energy energy Condition.
And it was at that point that I decided to look at a heat pump solution. For I basically knew that heat pumps were considerably more energy efficient than combustion boilers and I found the idea of using them compelling.
However, my consultants initially advised me that the site area available for either a slinky loop or borehole based ground source heat pump system was insufficient to provide more than a fraction of the thermal energy requirements, and the use of air source heat pumps would have required a sea of condensers on every balcony that wouldn't have been acceptable.
But it occurred to me that since an underground aquifer would have been ideal as the energy source for an open loop ground source system, might it be feasible to use the readily available water in the Thames as a viable alternative? I quickly established that the concept would work in principal, but in practice I found it impossible to find anyone who had actually done it.
Answering the question often posed by sceptical colleagues "If this is such a good idea why hasn't anyone done it before?" was extremely difficult – for there was no logical answer. But ultimately I did find an installation – but had to go, with the assistance of Mitsubishi, to inspect it – in Osaka, Japan. Only having done that was I able to persuade my colleagues and contractors that the system would indeed work.
The subsequent investigation and learning process has in fact, for my team and me, been all-consuming. It is never easy to do something that hasn't been done before, and it would undoubtedly have been much easier to install the combustion boilers.
But I am delighted we persevered. For this is a system that I truly believe is the thermal energy system of the future. It provides an opportunity to everyone dealing with projects in reasonable proximity to any open body of water to install a system that is likely to be five to ten times more energy efficient than a combustion-based system, plus – because we aren't burning any carbon-based gas or wood – it reduces on-site carbon emissions to zero. And the environmental benefits are further enhanced in that the electricity to run the system being is provided in our case by Ecotricity's wind turbines, which makes the whole installation zero carbon.
In fact, Mitsubishi, who have provided all our heat pump equipment, have calculated that by using the system this one development alone is saving over 500 tonnes of carbon being pumped into the atmosphere each and every year.
One other matter that I would mention as an aside is that because the heat pumps deliver hot water at around 43 to 45 degrees it has hitherto been necessary to either install chemical dosing or, as in our case, use an electric immersion to pasteurise the hot water cylinder. However, there is a new advance in water purification technology called the Brightwater 'Titanium AOP' (Advanced Oxidisation Process) that removes virtually all bacteria from the incoming mains water supply and therefore helps to optimise energy efficiency by removing the need for the electricity used for pasteurisation.
And finally, and in my view the most unique thing about the surface water source heat pump system is that it is totally scalable. For where the amount of thermal energy that can be produced by a slinky loop or borehole based ground source system is, as I said before, restricted to available site area – there is no such restriction with an open water heat pump system. For example it would only have been necessary to install one more abstraction pump and primary heat exchanger in the same plant room we were already building to supply another two megawatts to the neighbouring development.
And another key advantage of this system is its ability, with a control system that restricts the temperature to no more or less than 3 degrees of the prevailing water temperature – to reject heat to the river rather than the ground, albeit that is a regular issue more related to a cooling, rather heating cycle.
The provision of thermal energy – heat, hot water and cooling – accounts for over 50% of all energy consumed in the UK. Making gas or biomass boilers more efficient, with the aim of reducing carbon emissions is fine, But, by removing combustion from the equation, it is the adoption of heat pump technology in all its forms – and this system in particular – that will make the best, most significant contribution to reducing the UK's carbon emissions, and it is my hope that their use will rapidly become the norm.
Surface Water Source Heat Pumps
|Introduction from the developer of Kingston Heights||Mike Spenser-Morris|
|Current perspective from DECC||Graham Allardice, DECC|
|How to use the SWSHP Code of Practice||Phil Jones, CIBSE|
|Installing Surface Water Source Heat Pumps: Challenges and Opportunities||Nic Wincott, GSHPA|
|Introduction to the Fit for the Future Network||Paul Southall, National Trust|
|Thermal Transfer Fluid: Combating toxicity and improving performance||John Westerman, Kilfrost|
|Tour of the Kingston Heights riverside plantroom||Richard Venga, Mitsubishi|
|Tour of the Thames up to Hampton Court on The Georgian|