Penwith Housing Association (EST Retrofit for the Future Project (active):
Remote energy monitoring of a 1950’s built property in Cornwall, to be given extensive upgrading of the building fabric insulation and provided with a specially developed hybrid, multi source, renewable energy heat pump; the aim is to identify the extent to which carbon emissions may be reduced. A document written, for the press briefing on the HeatPod Project, by Denys Stephens, Sustainability Manager, Penwith Housing Association is attached.
Smart metering and environmental conditions monitoring were installed and commissioned on the 13th May 2010 to satisfy the basic requirements of the Technology Strategy Board, Driving Innovation Manual. The data logging installed at that time provides electricity meter readings for the total house usage, with a separate meter on the immersion heater; temperature and humidity readings are monitored in the lounge, hall, main bedroom and outside the property. Additionally, there is an air quality CO2 sensor in the lounge which, since the mechanical ventilation heat recovery unit (MVHR) was commissioned in phase 2, has resulted in substantially improved air quality (see chart below). The domestic hot water cylinder cold supply and outlet temperatures were also recorded; these sensors are to be moved when the heatpump is installed. The data will allow the building performance to be analysed prior to the completion of the retrofit work. Five minute logging intervals are required and the information is accessed remotely through a web portal receiving data using mobile phone SIM card technology. The monitoring installation was physically completed on the 29th September 2011 and additional monitoring equipment now profiles the operation of the heatpump, MVHR, Photovoltaic (PV generation and export) and the Pellet Stove in the lounge. This has been achieved using a combination of electricity and water meters, heat metering, duct, penetrative and air temperature/humidity sensors strategically placed within the installation.
The monitoring equipment is situated in the utility room at the rear of the property, adjacent to the main electricity meter and consumer unit. The slideshow below provides a photographic record of all aspects of the physical work undertaken between May 2010 and October 2011; led by professional design consultancy and internal PHA project management consultancy. It shows the substantial data logging required to fully and accurately analyse the performance of this type of project and illustrates examples of the electricity and water sub-metering, environmental temperature/humidity and CO2 sensors.
PHA Retrofit for the Future Project, Sennen,Cornwall
Penwith Housing Association anticipated that the retrofit contract work would be finished during the autumn of 2010, but unforseen problems prevented the commencement of work until March 2011 and the refurbishment was completed by August 2011. Detailed design by John Parker, Earth Energy Engineering Ltd and Geoscience Ltd, target an 80% carbon emissions reduction in the property (see link to PHA HeatPod Project on Partners Page). This has been achieved with high quality external insulation to the walls, triple glazing, loft and floor slab insulation. The ground/solar/air source heat pump provides renewable energy and is sited within the HeatPod, its efficiency further advanced through a heat recovery interface from a custom designed ventilation system and photovoltaic panels. The new technology coupled with energy efficient appliances and lighting, has replaced the existing solid fuel system and substantially improved the air quality within the home.
The following chart illustrates the substantial improvement in air quality following the commissioning of the ventilation heat recovery unit (MVHR)
Further equipment including water flow meters and penetrative flow/return temperature sensors in the ground loop supplying the heat pump and the system output from the condenser have been installed during the retrofit to monitor the new technologies being utilised. Also, a heat meter was specified by the EST to monitor the thermal efficiency of the equipment. Temperature/humidity recordings of the ventilation ducted air, and Evaporator LWT and Ground Loop EWT, identify the increased return temperature of the ground loop. Detailed analysis of the ongoing building and equipment performance will be undertaken by John Parker, Managing Director of Earth Energy Engineering Ltd and the designer of the project. Woodmead Energy Services will continue to support the accuracy and functionality of the monitoring equipment.
The following PDF file is the, as fitted version of the schematic diagram used for the design of this monitoring project.
Denys Stephens, Sustainability Manager, Penwith Housing Association has confirmed that the following information and blog is now freely available on the internet relating to the Retrofit for the Future Project.
The following link has has details and photographs of the work as it progressed.
The technology includes a 1.15kW roof mounted photovoltaic (PV) system which the installers estimate will deliver 920kWh/annum and a CO2 reduction of 523kg/annum. The following table from an approved calculator illustrates, in the five columns on the left of the table, calculated average daily and monthly output. The table has been enlarged to provide pulsed output data from an electricity meter connected to the remote monitoring system. The meter is recording actual yield at 5 minute integration periods in kWhe of energy delivered from the installed Photovoltaic array and will be updated monthly. Additionally, an export electricity meter identifies the surplus energy supplied to the grid.
|PVGIS estimates of solar electricity generation|
|Location: 50°4’46” North, 5°41’2″ West, Elevation: 88 m a.s.l.,|
|Solar radiation database used: PVGIS-classic|
|Nominal power of the PV system: 1.1 kW (crystalline silicon)|
|Estimated losses due to temperature: 12.8% (using local ambient temperature)|
|Estimated loss due to angular reflectance effects: 3.2%|
|Other losses (cables, inverter etc.): 14.0%|
|Combined PV system losses: 27.4%|
|Fixed system: inclination=42°, orientation=-45°||Yield comparison||Monitored Data||Monitored Data||Monitored Data||Monitored Data|
|Month||Ed||Em||Hd||Hm||Actual kWh/Predicted kWh||Average daily kWh||Average monthly kWh||Monthly Export kWh||Monthly Export %|
|Total for year||979||1180||856.85||326.24||38%|
|Ed: Average daily electricity production from the given system (kWh)|
|Em: Average monthly electricity production from the given system (kWh)|
|Hd: Average daily sum of global irradiation per square meter received by the modules of the given system (kWh/m2)|
|Hm: Average sum of global irradiation per square meter received by the modules of the given system (kWh/m2)|
|PVGIS © European Communities, 2001-2010|
|Reproduction is authorised, provided the source is acknowledged|
|See the disclaimer here|
*Diagnostics, using the chart below, generated from the remote monitoring equipment indicates a problem which is currently under investigation! It can been seen that export of electricity ceased on the 1st July 2012. The company who installed the photovoltaic equipment visited the property on the 2nd August 2012 and identified that the circuit breaker (mcb) protecting the PV circuit had tripped, there wasn’t any apparent problem with the equipment, which is working again.
The chart below is scanned from a web portal report illustrating the PV yield and Export energy over the period between the 1st October 2011 and 30th September 2012. It highlights that the photovoltaics equipment failed to deliver energy throughout the month of July 2012, the problem was identified using the remote monitoring equipment. Otherwise the equipment has performed well and would have achieved the annual estimated yield!
The photovoltaic equipment was commissioned on the 16th April 2011 and a meter reading, during a site meeting, on 10th May 2011 showed a yield over 24 days of 120kWh. Calculations based on the estimated output table above suggest delivery of 94.96kWh during the period, this highlights actual output of 26% over the pre-installation calculations. If this delivery continued for 12 months, annual yield could be approximately 1200kWh! When the the remote monitoring for the renewable energy technology is installed, it will provide regular updates on the performance, including the PV system.
The phase 2 monitoring equipment was installed during the week commencing Monday 25th July 2011; this will be connected to penetrative pipe temperature sensors and include flow meters, the electricity metering for the GSHP and the photovoltaic energy, a heat meter and ventilation duct sensors. The GSHP will be commissioned during August 2011 and the sensors will be operational before the next heating season.
Manual meter readings of the photovoltaic cells on 28/07/11 showed total delivery of 462kWh in 102 days since commissioned about 15/04/11. The calculation in the table above estimates 402kWh during this period. Therefore, the PV installation has delivered 15% more energy than the PVGIS estimates. A further manual reading on the 25th August 2011 showed delivery of 565kWh, the predicted output based on the calculator above 528kWh; which is 7% above the PVGIS estimates.
The project has already been acclaimed at the National Home Improvement Council (NHIC) 37th Annual Awards Luncheon, held in London on 24th November 2011, hosted by NHIC President the RT Hon Nick Raynsford MP, where it won the Category One, Best Local Authority and Registered Landlords Completed Modernisations and was runner up in Category Seven, Energy Efficient Improvements Using Renewable Technologies http://www.nhic.org.uk/award-2011/category-one/ http://www.nhic.org.uk/awards-2011/category-seven/, the links show Andrew Stunell MP, Parliamentary Under Secretary of State at the Department of Communities & Local Services, in the centre, presenting the awards to, from left, Mike Newell, Low Carbon Manager, EON UK; Norman Emberson, Member of PHA Environmental Working Party; Denys Stephens, Sustainability Manager & R4F Project Manager, Penwith Housing Association and Gerry Hargreaves, Woodmead Energy Services.
Also it won the Sustainable Construction Retrofit Award at the Cornwall Sustainability Awards Ceremony, held at the Pavillion Centre, Royal Cornwall Showground on Friday 9th December 2011 http://cornwallsustainabilityawards.org/2011-retro-fit.html, The link shows from left Paul Bright, Chief Executive of Cornwall Sustainable Building Trust (sponsors of the awards); Denys Stephens, Sustainability Manager & R4F Project Manager, Penwith Housing Association; Darren Gunn, Manager Penzance Office, Mears Group PLC (Project Main Contractors) and Dick Strawbridge, presenter of the awards.