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Energy Efficiency? Ask HMP/YOI Isis!
An interview with Gordon Ponsford – Head of Estates: YOI ISIS
by Steve Mitchell
Custodial sites throughout the UK, are constantly looking at ways and means of being more energy efficient. This not only helps the environment, in turn, assists in the crucial role of reducing costs. So it was fascinating to have the opportunity of finding out just what type of facilities are incorporated in a new build custodial site, given the benefit of starting with a clean sheet. With this in mind, I recently interviewed Gordon Ponsford to get first-hand, expert facts about the design and facilities put in place at HMP/ YOI Isis and whether they were measuring up to expectations.
 HMP/YOI Isis is sited within the perimeter wall of HMP Belmarsh to the east of London and on the banks of the Thames Estury. There are two house blocks (Thames and Meridian), both of a similar size. They are purpose built to Category B standard with a mixture of single and double cells. The total operating capacity is 622. The accommodation was completed in April 2010. The establishment also has an entry building, central activities centre, including the Learning Academy, segregation unit and PE Academy. It has a broad based curriculum that supports academic achievement, vocational training, interventions and PE activities. The interventions programme will be based on offender needs and will be subject to validation in the early years after opening. The regime is delivered in partnership with Kensington and Chelsea College.
Gordon Ponsford started his career as an apprentice for British Gas, became a service engineer for 20 years, which eventually led him becoming a Trainer. He joined HMP Ford, as an officer, and worked there for 18 months, then joined HMP Whitemoor where he was eventually promoted to Senior Officer. In 2002 he moved to HMP Lincoln then joined HMP Wellingborough in 2003 as Estates Manager, working on Health and Safety and environmental issues and was then promoted to Head of Estates at the newly built HMP/YOI Isis. He recently became Head of Estates at Brixton too, so has within his remit, both ends of the scale in terms of establishment age.
CR: Custodial Review
GP: Gordon Ponsford
SM: I understand that Isis was built to the highest sustainable standard for energy and water conservation?
GP: Yes, a major consideration had to be how to save energy, use less water and cut waste. The construction of HMP/YOI Isis is built to the latest energy efficient standard and has a grade B, energy rating certificate. Additionally, the establishment received an excellent rating in BREEAM (BRE Environmental Assessment Method) for all buildings. A top of the range Building Management System was also installed in order to achieve these aims.
SM: Lets start with water conservation. How much water is collected and how it is used and stored?
GP: All the buildings across the site have grey water feeding the toilets. ‘Grey water’ is what we call water that is not suitable for drinking but is suitable for flushing toilets and watering gardens. This grey water is harvested from the roof using the rainwater down pipes and then held in 8 large underground tanks, which each can hold 10,000 litres of water. This is then pumped to storage tanks in the roof of each building, these hold 2,000 litres. All cold water, including grey water, is fed through a UV lighting system to destroy any bacteria. All toilets are short or long flush and so save water, provided they are used correctly of course. So there are three sets of water supply pipes across the site, two provide potable or drinking grade hot and cold water and one for grey water which feeds the toilets.
 SM: Water usage, how is that controlled? How much money has been saved with this system?
GP: All water going into the cells is operated using electronic timers; this also includes the toilets. By this method, if they are used more than 4 times in 30 minutes the system will not let it come on again for another 30 minutes. This stops excessive water usage, again saving energy and costs. The same system operates the showers. Electronic timers control the time element across the site and the showers only come for a pre determined time then shut off and will not operate till the person has moved away from the shower head. It’s not just the cost of the water that is saved, it’s also the electrical energy required to pump it around the building. This system saves considerable water and energy usage. It’s too early to tell at this stage how much is being saved as the building is so new. However we already measure the quantity of water coming in against the amount of sewage going out we will eventually have the figures that we can use to maintain and improve on in the future.
SM: Is there a great deal of hot water storage involved?
GP: Very little. The hot water is produced using plate heat exchanges, which heat the water very quickly and maintain it at that temperature so it also controls Legionella. Because of this ability to heat water so quickly we keep our hot water storage to a minimum. This means it isn’t constantly cooling down thereby keeping the energy used to heat water to an absolute minimum.
SM: I understand you are using a Biomass Boiler System, why?
GP: The Biomass is a 500K/W boiler unit, which is deemed to be 80% efficient. It uses wood chip as a fuel, which we acquire from a firm only 7 miles away, so transportation costs are kept to a minimum. It has to be that close to qualify as a ‘green’ power source as it would be ridiculous to have to bring the fuel hundreds of miles just to burn it in a ‘green’ boiler!. A full shipping container of wood chip produces ash that fills only a plastic bin liner bag. This is then scattered over the grounds, so reducing landfill costs. We keep one full container on site at any one time. The Biomass boiler gives us 70% of our heating needs plus hot water when it is operating. However we have only run the system to commission it so far. This is because it must either be on fully or turned off and the prison, as we speak, isn’t yet fully occupied so we do not yet need enough heating to justify it operating.
SM: How much money would you save when it is?
GP: Again, it’s too early to tell exactly. We know from its figures it will save money but until it has been operating for a while we will not know exactly. We shall monitor as we go along and compare usage and costs.
SM: You are also using one Combined Heat and Power (CHP) boiler. Why not use more?
GP: Running the whole prison on CHP boilers alone would take up too much room within the establishment. Although the system is 95% efficient and produces around 25% of our heating and lighting and around 20% hot water. We would need to install them in at least 5 locations across the prison and that simply isn’t practical.
 CR: What other systems do you have, what back up and how do you operate them all as a practical system?
GP: The Biomass boiler is our main system in cold weather conditions but because it is fired by wood chip you cannot just turn it off and on as a gas system can. CHP is used in the summer months and as a back up in winter. Both systems were incorporated in the overall design to maximise energy efficiency throughout the whole year. The CHP systems are able to produce 20% of our electric supply. We also have 8 Broag gas boilers, which are 90% efficient, and these are used as a top up heating in extreme conditions. They are also used for when other systems are being serviced.
SM: You have a heat recovery system on site; can you explain what that’s all about?
GP: Take an office – mine for example – which has a radiator for heating and an air supply system because there are no windows. This system supplies warm or cool fresh air. Any excess heat is extracted and sent down to a heater battery. From there it is re-piped back into the flow coming back into the building, so in effect you’re recycling the air coming into the building and saving the heat it contains.
SM: What about the lighting systems, how are they controlled to save energy?
GP: Much of the lighting is controlled by movement sensors and this is computerised to optimise the areas usage. There are not many light switches in this prison! The lights that are not controlled by movement sensors are usually in the classroom because they have overhead projectors in the room, so the lights need to be turned off manually. All the lights are the energy efficient type T5. The other area that is manually controlled is the plant room, this is for health and safety reasons. However they are turned off automatically at 9pm unless there is someone in that room. In addition specific lights come on at the weekend in areas such as the academy, again for health and safety reasons and to assist security staff when they are patrolling.
SM: I understand there is an air conditioning system in some areas. Why in some areas and not others?
GP: This ensures cost effectiveness. A heat pump system supplies cool or warm air to offices and classrooms across the site. This is a far more cost effective method than having to install a wet radiator system, as some areas, such as the academy, are too large for radiators because the ceilings can be up to 15 feet high.
SM: You have something on site call ‘Big Hanna’, can you tell me what that does?
GP: Big Hanna is a machine which turns our waste food into compost. Waste food is fed into a pelletiser, which effectively squeezes the water from the waste food, which then turns the waste into small pellets. These pellets are then placed in Big Hanna, which is like a circular drum. Heat is then applied while the drum rotates. The end result is to turn our food waste into perfect compost for the garden area, thereby saving our waste having to go to landfill. We may also be able to sell it across the prison estate.
SM: Can I come to the question of transport; what vehicles do you use?
GP: We have a Toyota Prius hybrid car. To keep our energy consumption as low as possible this vehicle will run on EV electrical mode up to 31mph for 1.2 miles. Apart from that, there are reduced charges for fuel, car tax and general running costs. In addition there are no congestion charges for this vehicle in the London area. We also have two vans that run on diesel.
SM: Ever thought about running them on cooking oil?
GP: Eh: we haven’t thought about that, perhaps it is something to consider for the future!
SM: Thanks for talking to the Review Gordon.
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