In June London based consultants EnergyExcel engaged Fairfield as Commissioning Managers for a new £4.1m CHP installation in Barnard Castle.

The CHP scheme built by ENER-G is driven by a pair of 1.15MWe natural gas engines and will generate 2.3 MW of electricity together with ‘free’ steam and hot water for building heating. The installation is expected to deliver around £1m/year in savings and pay back in less than 5 years.

This contract follows the successful implementation of a similar but larger scheme in Hertfordshire earlier this year and Fairfield is shortly to be engaged again to lead commissioning at a third site. As Jon Truman from Fairfield explains, each of the three CHP schemes will involve Fairfield in different ways, “In each case we’ve integrated the controls package that comes with the CHP plant with the local Building Management System (BMS). The first site had disparate BMS systems in its various buildings none of which could provide the necessary supervisory control so we provided a PLC-based solution to stitch it all together. For this Barnard Castle site our role has been to supervise the overall commissioning rather than provide the controls, but the controls have simply involved a straightforward connection between ENER-G’s package and the local site-wide Trend BMS system. For the next job we’ll be supervising commissioning again where the CHP plant will be interfaced with a Schneider TAC BMS, and of course Fairfield Generation Systems is a BMS partner for Schneider.”

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We’ve all heard stories of renewable energy systems that have never really worked, and Fairfield has heard one or two theories about why that happens. For example, a senior manager at another Local Authority once explained to us that the main contractor delivering new schools tended to install renewable energy systems themselves rather than use a specialist subcontractor, because “all that was required was to tick the box to get the grant funding”. This seems to resonate with similar stories we’ve heard about biomass boilers being installed under the Merton Rule and never commissioned. Part of the problem seems to be that the no one’s sure what’s expected of renewable energy systems, and perhaps in some cases nothing is expected. Main contractors seem to be able to get away with handing over buildings that don’t work.

Earlier this year Fairfield inspected a number of buildings at a different Local Authority again in order to develop a specification of works. Generally we were looking at heating systems in elderly people’s homes, swimming pools, libraries and council depots. In many cases the heating systems seemed to be thirty or forty years old, and in most of the elderly people’s homes we’d find the heating running full blast and all of the windows open. The usual stories were of radiator valves that hadn’t worked for years, of buildings that were boiling at one end and freezing at another and of piecemeal improvements where no one had reviewed the whole operation of the site. Very few buildings had zones, few had more than one thermostat and many relied on regular visits from the Authority to crank the heat up and down a bit as the weather changed. Clearly it’s not just a problem in one Authority and it’s not just new buildings with renewables that need re-commissioning.

So, let’s return to our case in point, it’s a primary school in the midlands built and handed over in 2007. It’s not a BSF school or any other kind of special deal, it’s just a regular Authority-built school, and it’s was clearly intended to demonstrate the state of the art. The school is elaborately furnished with renewable energy systems and care has been taken to make sure that these systems are accessible to staff and students so that they can be used as a teaching resource. It’s a thoughtfully designed, carefully built school where no corners were cut and decent energy systems were installed by proper specialist sub-contractors.

There are eighteen 110m bore holes under the netball court driving two ground source heat pumps for space heating; there is solar thermal for the direct hot water; a solar PV array with web-enabled inverters, a 25000 litre rainwater collection tank under the car park, about 30 heating zones and a site-wide BEMS system managing the whole lot. The BEMS has a ‘student interface’ with a 50 inch screen in the hall and a touch panel allowing students to monitor and control the whole plant and learn about energy systems.

The problem is something went wrong at hand over, or perhaps afterwards. Either no one knows or no one’s telling, but you get the idea that maybe the people who were pushing at the boundaries moved on and everyone else wasn’t quite ready to operate and maintain all that new-fangled renewable stuff. Reasonable efforts to get the things working have only made the situation worse.

Fairfield first became involved at Easter this year after hearing about the problems and making a direct approach to the school. The head teacher was cutting core budget so he could afford his electricity bill – something needed doing soon.

Well it’s still a work in progress, but Fairfield is nearing the end of the fixes. So far we’ve found that due to a plumbing error the solar thermal never heated the hot water, so the water was really being heated by 12KW of backup immersion heaters. The direct hot water circulation system wasn’t properly lagged so the whole 12KW was being lost around the building and the immersion heaters ran constantly, in effect acting as the space heating.

The underfloor space heating was in fact in serious trouble. About a third of the actuated valves had been physically broken in attempts to get them working, but moreover the swapping in and out of broken valves meant that many of the wires were crossed between the thermostats and their valves. So for example, a thermostat in a corridor managed the underfloor loop in a cloakroom and the ICT suite was regulated by a thermostat in a distant classroom.

You’d think that would be enough, but it goes on. The rainwater pump was starting and stopping every 30 seconds trying to pressurise the cold water system, with all of those start-stops it probably made quite a contribution to the electricity bill. What’s more the rainwater tank was always empty. It soon became clear that the system was set three-times over-pressure and had therefore destroyed all of the washers in the taps and toilets. The whole system leaked and the pump repeatedly kicked-in to compensate for the leaks.

Next week we’ll sorting out why the ‘web-enabled’ inverters on the PV system were never integrated into the BEMS and then we’ll be looking at why data logging and the student interface have never been commissioned.

Is the Head Teacher happy now? Possibly. Over Easter we reduced the monthly electricity bill from £1800 to £1200, now the Head’s looking to get it to down to £900 and then we’ll be deemed to have succeeded. It’s not clear what kind of science was used to determine this target of a 50% saving but it is a target that we might reasonably hit. Then we’ll be ready to write the case study and report on the payback time, but at the moment the usual 1 to 2 years looks reasonable.

Fairfield has been commissioning systems for nearly 25 years, so we’re used to methodically working around large and complicated systems and taking a reductive approach to problems. We’re not plumbers, but we have plumbers we call upon. We’re not solar or heating specialists either, but again we know the right people. However we are specialist ‘systems integrators’ and ‘commissioning engineers’ and we’re the right people to look at a whole system, to see a job through to the end, and to get it working!

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In line with the general thrust of Coalition policy with regard to micro-generation the scheme prefers support for the industrial and commercial sector; the public sector; not-for-profit organisations and communities rather than the domestic sector which has limited funding in the first phase and catches up in a second phase planned for 2012.

Of particular interest is that:

• The RHI will be funded from general Government spending, not through the previously proposed RHI levy
• Tariff levels have been calculated to bridge the financial gap between the cost of conventional and renewable heat systems, with additional compensation for certain technologies for an element of the non-financial cost
• Eligible non-domestic installations completed after 15 July 2009, but before the start of the RHI, will be eligible for support as if they had been installed on the date of its introduction

Details of the scheme, including tariffs, can be found at: http://www.decc.gov.uk/rhi/

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The outcome of the survey will determine the programme for an Energy Briefing Day jointly organised by Fairfield and UKSPA and scheduled for Autumn 2011. The Briefing Day will be open to all, and free of charge to UKSPA members.

Fairfield’s skills in Commissioning and Optimisation and in Joined-up Energy Systems (Local Smart Grids) are particularly relevant to the campus situation where proper tuning and co-ordination of existing energy systems is likely to offer significant energy savings with a very fast Return on Investment.

Many Science Parks are located out-of-town and have the open space required for wind turbines or heat pumps. However before any such investment can be made, the park operator (which usually controls the land) and tenants (that pay the energy bills) will need to work together to agree an Energy Strategy.

The survey begins a dialogue with UKSPA members by asking them about their concerns about energy costs and legislation and enquiring about their aspirations for energy saving. Updates will be posted here as the picture unfolds.

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The Grid, which will include several homes and types of local generation, will serve as a fully functioning mini-grid enabling the University to carry out Smart Grid research and development projects in a near real-world environment.

Fairfield will help the University to design and install a supervisory control scheme to ensure the safety and operability of the plant.

A fuller joint statement from Nottingham University and Fairfield will follow.

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Most newly built schools have been furnished with state-of-the-art heating, lighting and ventilation systems including photovoltaic panels, solar thermal water heating and heat pumps for space heating. In addition the demands of new curricula mean that schools have complicated and dynamic requirements for heating and lighting. The collaboration combines IESD’s expertise in schools with Fairfield’s capacity to deliver and support a practical control solution.

Prof Marjan Sarshar, the Director of IESD, welcomed the initiative; “IESD has been involved in the human factors influencing the design of BSF and other new schools in Leicestershire for over five years. Most recently we’ve been looking at the issues that have arisen post occupancy in the first four BSF schools and have recognised that the changing pedagogy and the difficulty in sustaining complex energy systems are significant factors. It has become clear to us that we must develop a more demanding set of requirements and a more sophisticated level of control for the building systems. We are extremely pleased to be working with Fairfield to make sure that schools in all authorities across the country can benefit from this analysis.“ 

Director of Fairfield Generation Systems, Peter Rowe, said; “Many of us will have first hand experience of the difficulties in heating a school, having weathered a red hot classroom or a freezing cold gym. Furthermore, the recent investment in new schools has introduced sustainable energy systems that represent a serious management challenge for even the most experienced Premises Officers. Building Energy Management Systems in modern schools have to cope with multiple modes of operation, a large hall might be a sports venue one day and an exam room the next – with completely different heating and lighting requirements. Similarly a teacher may need to temporarily bring the temperature of a classroom down to near outdoor temperatures to facilitate a mixed indoor-outdoor lesson. IESD has considerable experience in describing the human requirements that will ensure a school’s systems are practical and that the learning environment is comfortable; this complements Fairfield’s skill in specifying and commissioning control systems for lighting, heating, ventilation and air conditioning. The partnership will have the capacity to design and install tailored solutions for schools and other public buildings which will introduce an improved level of control, delivering both comfort and energy saving.”

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Balancing the National Grid is one of the major challenges in integrating intermittent renewable sources into Britain’s electricity supply. We’ve already seen an occasion when the National Grid paid a wind farm to turn off their turbines because their erratic surges were unbalancing the system. Scottish Power received £13,000 for closing down two wind farms for over an hour on May 30th 2010 (source).

There is very little energy storage in the National Grid so real-time matching of supply and demand is essential. The roll out of the new Smart Grid, which can react much more quickly to match supply and demand, depends on a ‘dynamic demand-side response’. That is, when demand peaks, prices go up and consumers switch off.

Consumers are often able to make choices about when they buy electricity. Using intelligent controls non-essential loads can be interrupted (e.g. fridges and airconditioning), and with a little forward planning heat can be sunk into a building when the electricity price is low, reducing needs at the next peak time. Similarly organisations with some on site micro-generation might choose to use surplus energy for pre-emptive heating and cooling rather than sell it to the Grid when the price is low.

Consumers with their own microgeneration capacity effectively have their own Local Smart Grids and can choose when to buy and sell energy with the national Smart Grid. As Smart Meters are rolled out those of us on the demand-site will become increasingly interested in the price of energy and the art of managing it. Just like currency trading there will be a good time to buy and a good time to sell.

This kind of user response is key to the design of the Smart Grid and supports the overall objective of balancing the system. Fairfield is developing strategies for Local Smart Grids that will make maximum use of the (often limited) local energy storage to both save consumers money and help the country to meet its need to flatten the load pattern. Using a little bit of local storage to buffer demand on a wider network is not a new idea, the cold water storage tank in your roof buffers the demand on the water network.

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