Dynamic demand side management of heat pump integrated with thermal - PowerPoint PPT Presentation

Dynamic demand side management of heat pump integrated with thermal energy storage Christopher Wilson Loughborough University – 29th June 2015

Introduction  Project Title  Dynamic demand side management of heat pump integrated with thermal energy storage  Scope of the project – Aims and Objectives  Methodology  Analysis  Results and Outputs  Summary

Project RETROFIT Scope  Radiators +60 ° C DSM  Minimal Disruption  Retrofit – “plug & play”  Suitable for existing trade  Max 80 ° C flow temp workforce  Heat Pump Seasonal COP – min 2.5 to Thermal Storage be renewable – what is the Direct Indirect max achievable? Heat Heat  Thermal comfort – gas  Electrical for DSM. Heat Demand  Cost effective over life cycle.

Other energy storage options… Thermal Storage  Latent – PCMs  Thermochemical Sensible heat storage  Increased storage capacity  600 litre buffer tank DSM  Reduced storage volume  14 kWh useful – delta-T 20 (55-75 ° C)  Energy loss - 1 ° C/hr  Lower heat pump heating coil  Upper house central heating coil  Cylinder stat Heat Pump Thermal Storage  Temperature monitoring  De-stratification pump  Needs to be high capacity – low energy loss Direct Indirect  Compact for domestic situation Heat Heat  Meaningful thermal store over 24 hours to realise DSM capabilities Heat Demand

Electric Wind DSM Tariffs Penetration Daily electricity price variation DSM Wind production forecasting…  Peak around 15:30 – 19.30 Wind farm dispatch down across Ireland –  Managing wind energy variability 2012  Price not lowest at night –  Ability to flexibly control DSM tools  Instead of turning of wind farms – Turn on some flexibility to balance the grid heat pumps  Energy potential utilised Heat Pump  Increased wind energy penetration Thermal Storage Direct Indirect Heat Heat Heat Demand

Methodology Retrofit:  Bypass existing gas boiler  Remains in place as backup  Uses existing heating controls 2 scenarios with heat pump: 1. Heat house directly 2. Heat house indirectly via buffer and storage tank

House heated via buffer tank  More heat delivered from heat pump than delivered too house  Heat pump is on reheat mode – maintains buffer at 75 ° C  Daily heat loss of 20 kWh in some cases – 82% efficiency

Benefit of buffer tank  High instant power  House thermostat quickly satisfied  Heat pump running long durations – benefit might not be justified.

Dynamic DSM Controller via Raspberry Pi Raspberry Pi  Credit card sized low cost computer - £30  Enables physical computing – ability to control relays + measure sensor inputs (buffer tank temperature)  Write python software to control input and output pins  Connected to network – retrieves internet data and network control – real time forecast demand  Email alerts to phone for malfunction and switches off leaving heat pump in default direct heating mode

Dynamic DSM Controller via Raspberry Pi Normal Operation – Rpi Control – Charging Rpi Control – Using Direct Heat  Benefit to store stored heat  House call for heat  Buffer tank less  Benefit to use  Relay A normally than 75 ° C  Buffer tank > 55 ° C closed  RPi Pin 12 closes  RPi Pin 11 closes  3PV energises –  Relay C energises –  Relay A energises – direct heating HP on Heating pump on  Relay B energises – HP on

Results & Further Work Initial testing: 1. Raspberry Pi control - dynamic switching between direct and storage mode  Only recently installed – further analysis required – tweaking of input parameters  Testing using forecast wind electricity production  Testing using real time electricity pricing  Formulation of optimised demand side management method – Renewable Electricity Tariff  Machine learning techniques for true plug and play “ dsm adaptor”  Specifications of HP and thermal stores required for efficient DSM

Summary The project goals…  Heat pumps to meet the energy demand of domestic house  Retrofit system and integration  Thermal storage – improve heat pump integration  Thermal storage – DSM role  Demand side management control  COP of HP needs to improve  Thermal store needs to increase capacity/reduce in size  DSM control needs further optimisation to justify its use and incentivisation

Thanks for your attention. Any Questions?