Waste Heat Recovery & Heat Pumps Dave Pearson Star Renewable Energy An introduction discussing - Why do Maintenance? Highlight factors such as: Reliability – Confidence in the plant and low human interference Efficiency – Getting the best from your asset at all times Health & Safety – Being a low risk and ensuring no failures that could lead to accidents Legal Compliance – Fulfilling the necessary compliance eg F-Gas, Written Scheme of Examination, PSSR etc Uptime/Productivity – Ensuring the plant is available at all times to deliver the necessary cooling demands Environment – Keeping the plant in the best condition to avoid losses that may impact the environment eg refrigerant leaks Corporate and Social responsibility – A demonstration that your business does what is right! All of these are inextricably linked by money, but the investment in maintenance can capitalise in your return in all of them.

SRE & Heat Pumps

SRE & Heat Pumps ASHP Up to 62C hot water flow WSHP Between 20C and 90C Hot water flow

Big Heatpumps @ Drammen

The Basics – WSHP

The Basics ASHP

Refrigeration Cycles Relationships between the different stages in the cycle

Refrigeration Cycles Increase the source Temp, Decrease the Hot side Temp

Refrigeration Cycles Add in a Subcooler

Refrigeration Cycles Add In A Desuperheater

Heat recovery summary Not much for free- the more you try the more you get Beware of “fake-news” More “considered” plant likely to be better in general and offer more heat recovery

Operating Temperature – Source Side

Operating Temperatures – Hot Side This is the district heating side of the heat pump system Doesn't have to be 82/71 Deg C – This is for GAS! Doesn’t have to be 90 Deg C just because we did it at Drammen

System Design - Basic 2MW 55/75 from 8/5 Deg C Source Water entering condenser and oil cooler independent of each other and mixing to achieve the desired outlet temperature COP of around 2.2

Including a Desuperheater COP increased to 3.0

Including Subcooler (but no Desuperheater) Including a Subcooler but no Desuperheater takes the COP to 2.99

Both Subcooler and Desuperheater COP now at 3.08

What About Subcoolers & Desuperheaters?

Multiple Heat Pumps – Parallel or Series or Both? 3 heat pump system Parallel Vs Series/Parallel Combination for 2MW 55/75 from 8/5 Deg C Source Parallel gives COP: 3.08 Combination gives COP: 3.39

Single, Double, Triple

More Complex

18MW District Heating

“Free Cooling” Evaporator outlet water. Smart city planning. Reduce cost for electric cooling on site.

Hot side flow/return Temp (Deg C) 55/75 Source Side Temp (Deg C) 8/5 Motor Losses and Source Pump Power! Are you being quoted a Shaft or Absorbed power COP?? Hot side flow/return Temp (Deg C) 55/75 Source Side Temp (Deg C) 8/5 Number of Units 1 Heat Pump Capacity (kW) 1049.5 Power - Shaft (kW) 332.4 COP 3.16 Motor Losses - Say 3% (kW) 9.972 Inverter Losses Say 3% (kW) 9.67284 New COP 2.98 Source Pump Power (kW) 20 Final COP 2.82

Why Should We Care????????? Larger central energy plants = lower cost (£/kW) RHI Waste heat provides opportunity for very high COP’s Carbon reductions (Carbon targets) The electricity gird is decarbonising every year. Why wouldn’t you want technology that is 2050 ready?

Gas Elec HP1 HP2 Fuel(kWh) 3 10 Efficiency(%) 85% 100% 600% 300% How much is that doggy in the window? So 1kWh from 4 sources…………… HP1 = Heatpump COPh 6.0 HP2 = Heatpump Coph 3.0 but RHI eligible…………………………...   Gas Elec HP1 HP2 Fuel(kWh) 3 10 Efficiency(%) 85% 100% 600% 300% RHI(p/kWh) 5.5 nett Fuel(kWh) 3.53 10.00 1.67 3.33 nett Heat (kWh) -2.17 nett Fuel (KgCO2 /kWh) 0.225 0.35 0.058 0.117

Looking To The Future

Main rates of CCL Carbon Reduction Commitment and Climate Change Levy CRC end Oct 2019 CCL takes up the reins. Main rates of CCL   Taxable commodity Rate from 1 April 2016 Rate from 1 April 2017 Rate from 1 April 2018 Rate from 1 April 2019 Electricity (£ per KWh) 0.00559 102% 0.00568 103% 0.00583 145% 0.00847 Natural gas (£ per KWh) 0.00195 0.00198 0.00203 167% 0.00339

The choice? Listen to “Policy Needs” and act for the future now....... Or wait till the Carrot is a just a faded memory!