DEMAND SIDE ENERGY OPTIMIZATION WITH HEAT PUMP SYSTEMS

Current reality of availability of useful energy User End Power Station End For every unit of electrical energy consumed at user end, 4 units of equivalent energy is expended at the power generation end.

Electrical costs & availability Electricity costs are around Rs. 8.00 / kW in major cities for residential and Rs. 10.00 - 12.00 / kW for commercial establishments like hotels. These costs are proving to be a major burden on consumers Availability of electric power at will is also a problem in almost all parts of India excepting cities like Mumbai. Provision of backup DG sets involving higher costs of DG based power (Rs. 14 - Rs. 16/ kW) has become a norm rather than an exception

Relative costs of fuels/electricity HSD prices have increased from around Rs.20/ltr in the late’80s to currently around Rs. 45/ltr (225% rise) Natural Gas has increased from around Rs.8/m³ in 2000 to currently around Rs.29/m³ (363% rise) Electricity has increased modestly from around Rs.4/kW to currently around Rs.8 – 10 /kW (100 + %) The future fossil fuel price hikes will far out pace electricity price hikes There is merit in actively utilizing electricity as an energy enabler for heating

Hotels & Hospitals Hotels (& Hospitals) use Diesel fuel or Natural gas steam boilers / hot water generators for hot water production. A 150-200 room hotel facility with a hot water consumption of around 50m³ /day spends around Rs.13,000 / day in fuel costs.

Residential Complex High end apartment buildings necessarily have to resort to backup power due to unreliability of grid power, and also for emergency requirements like lifts and elevators A high rise apartment complex with 100 apartments of 3 bedrooms each will have a connected power load of 900 kW with electric geyser requirements for hot water (3 kW / Geyser). The backup power has to factor this into account This high capacity connected power which is at best is used only over 1 - 2 hours a day puts a tremendous pressure on the grid availability. The carbon foot print to cater to this peak requirement puts a tremendous burden on the system. Backup power has also to have fuel storage

Demand side management at user end A differentiated approach to achieving energy optimization and efficiencies…

There is a need for a more efficient heat source for various hot water requirements Can we leverage electricity not as a heat source, but as a heat energy enabler? Can we use it as an input to magnify the heat source? Can the current operating costs be reduced to 1/3? Is there a way by which electricity can make available economical utilizable heat energy for Hot water Generation ?

Heat Pump Systems – the energy source of the future Effective solution to heating and cooling applications Globally accepted for providing safe, reliable heating and cooling at affordable prices Capable of highly cost-efficient energy applications as compared to fossil fuel-fired heat generators and boilers Cut global carbon emissions by nearly 8%

Heat Pumps – Key aspects Heat Pumps absorb thermal energy at lower temperatures (heat source ) and upgrade this energy at high temperatures ( for heat duty ) using electric power as an enabling medium, that also convert it into heat energy at the higher level of temperature CO2 emissions with Heat Pumps are 0.14 kg CO2 / kWH, with fuel oil it is 0.31 kg CO2 / kWH and with gas it is 0.24 kg CO2 / kWH If electric power for Heat Pumps is made available from wind / solar, the ecological benefit is virtually nil CO2 emissions

Heat Pump System The window air-conditioner is an air to air Heat Pump which pumps out the room heat to the outside ambient The Heat Pump System to produce hot water is an air to water Heat Pump, or a water to water Heat Pump Whilst heating up water on one side, it simultaneously cools air on the other side or produces chilled water which can be used for air-conditioning It therefore can give you the double benefit of producing hot water and comfort cooling at a much reduced cost In North India when you do not need cooling in winter, it can produce only hot water, for winter heating (as an air to water Heat Pump which can operate at an ambient of - 10°C)

Heat Pump Systems - Operating principle Electric motor power – enabling medium that converts itself into heat energy source at higher level of temperature B Compounding effect of utilizable energy A+B Absorb thermal energy at lower temperatures A

Heat Pump application based heat energy use Utilizable process heat energy Energy expended at User End Every unit of energy expended is magnified 3-5 times as utilizable energy

Financial implications For generating 1 million kcal of heat through different fuels at a thermal efficiency of 85%.   FUEL SOURCE HEAT VALUE OPEX HSD 142 ltrs @ Rs. 45 / ltr 8,300 kcal / ltr Rs. 6,390 / - Natural Gas 138 m³ /hr @ Rs.29 / m³ 8,500 kcal / m³ Rs. 4,002 / - Furnace Oil 120 kg / hr @ Rs. 40 / kg 9,800 kcal / kg Rs. 4,800 /-

Heat Pump relative advantages Heat Pump 1million kcal = 1163 kW of Heat output Heat input = 333 kW @ Rs. 8 / kW. = Rs. 2664/- FUEL BASED OPEX HEAT PUMP OPEX SAVINGS ACCRUED HSD – Rs. 6390 /- Rs. 2664 /- 58 % Natural Gas – Rs. 4002 /- Rs.2664 /- 33 % Furnace Oil – Rs. 4800/- 45 %

Simultaneous heating and cooling The Heat Pump can be designed and configured as a multi mode machine. To generate only hot water from ambient air To simultaneously generate hot water and cooling energy. To generate only cooling for comfort Hotels and hospitals continuously need air-conditioning, and therefore on a multimode basis, the OPEX costs of a Heat Pump come down to around 20% of fuel fired boilers Differential cost of investment of the Heat Pump System could be recovered well within one year. Retrofits payback possible in one year

Increased savings with simultaneous heating & cooling 1163 kW of heat makes available 763 kW OR 217 TR of cooling This results in a saving of 174 kW of electric power Net energy consumption 388 kW – 174 kW = 214 kW Effective cost of Heat input 214 kW @ Rs. 8 / kW. = Rs. 1712/- FUEL BASED OPEX HEAT PUMP OPEX SAVINGS ACCRUED HSD – Rs. 6390/- Rs. 1712/- 73 % Natural Gas – Rs.4002/- Rs.1712/- 57 % Furnace Oil – Rs. 4800/- 64 %

MEASURES OF PERFORMANCE - HEAT PUMPS (A) Thermodynamic C.O.P = Heat output in kW (Heating) Power input in kW Thermodynamic C.O.P = Combined heating + cooling output in kW (Heating + Cooling) Power input in kW Commercial operative OPEX C.O.P = Heat output in kW Net power input in kW Net power = Power input – Estimated power saving of cooling generated

MEASURES OF PERFORMANCE (B) AIR TO WATER C.O.P 3.5 IN PENINSULAR INDIA (55 – 60 °C) WATER TO WATER C.O.P 3 units of heating + 2 units of cooling 5 COMMERCIAL OPEX C.O.P Power input = 1 kW Heating = 3 kW Cooling = 2 kW = 0.569 TR …(1 TR = 3.516 kW) Power for cooling (kW / TR for chillers = 0.75 kW/TR) = 0.569 x 0.75 = 0.427 KW Net power = Power input - Power saved in free cooling = 1 kW – 0.427 kW = 0.573 kW Commercial OPEX C.O.P = 3 kW / 0.573 kW = 5.235 C.O.P of 5.235 as compared to 3.5 is an increase of nearly 50 %. Therefore, wherever combined heating & cooling is feasible, it becomes the obvious choice.

Heat Pumps – Working Fluids (HCH) Most Heat Pumps operate in the subcritical zone where the major part of the heat transfer is by condensation of the working fluid in the vapor phase. Available process heat temperatures are up to 80 °C. Most Heat Pumps for these heat duties are with Halogenated Carbon Hydrides such as R-134a, R-410a and R-407c which are HFCs, and are eventually also on the agenda for phase out. Halogenated Carbon Hydrides would be superseded by Natural working fluids such as CO2, which can currently generate useful process heat temperatures up to 90 °C or higher .

Heat Pumps – Working Fluids (CO2) With CO2 as the working fluid temperatures up to 105 °C is also possible and in development. The CO2 base Heat Pump cycle operates in the Transcritical / Supercritical thermodynamic zone and dissipates heat cooling of gas vapor and not condensing vapor. Operating pressures are in the region of 130 bar. For a combined heating ( 65 °C ) and cooling duty ( 7 °C / 12 °C ) the overall Coefficient of performance would be in the range of 4.8 to 4.9 for R-134a. For a combined heating ( 90 °C ) and cooling duty ( 7 °C / 12 °C ) the overall Coefficient of performance would be in the range of around 6.3 for CO2. Unlike the potential environmental hazard of the Halogen Carbon family of working fluids, CO2 is a natural substance which is captured from natural metabolic cycles.

Sub Century Celsius Heating Applications Temperature up to 65 °C Pharma, Food COP – 5 (3 of heating + 2 cooling) Temperature up to 75 – 80 °C Chemicals, Textiles COP – 3 ( 2 of heating + 1 cooling ) Temperature up to 90 °C Dairy, Flexible packaging, White Goods / Auto

Case Study – Pharma Industry (Cosmetics)

Need Assessment Process hot water heating for Cosmetic manufacturing involving pure water. Currently Furnace Oil Boiler is used for producing hot water. Efficiency of Furnace Oil Boiler is 85 % , it is used to produce steam which is used for heating water, so considering steam and condensate losses the net efficiency is 80 %. Cost of Furnace Oil = Rs. 40 / kg Location of the plant is in an Industrial area in North India where Hydro power is available , so the cost of power is around Rs. 6 / kW. Hot water requirement is around 12,500 LPH which has to be heated from 30°C to 80 °C. Heating capacity required = 12500 X 50 = 625,000 kCal / hr = 727 kW

OPEX Analysis Furnace Oil Boiler Heat Pump System Efficiency of boiler = 80 % Calorific Value of Fuel = 9800 kCal / kg Fuel Consumed = 625000 = 79.7 kg / hr 0.8 X 9800 Cost of fuel = Rs. 40 / kg Total OPEX / hr = 79.7 X 40 = Rs. 3188 / hr Heat Pump System Heating Capacity = 727 kW Cooling benefit = 437 kW = 124 TR Power Consumed = 290 kW (C.O.P = 2.5) Power saved due to cooling benefit (0.8 kW / TR) = 124 X 0.8 = 99.2 kW say 99 kW Net power consumed = 290 – 99 = 191 kW Total OPEX / hr= 191 kW X Rs.6 = Rs. 1146 / hr

Accelerated payback Difference in OPEX = 3188 – 1146 = Rs. 2042 / hr Annual savings in OPEX Rs. 2042 X 16 hours X 325 days = Rs. 106 lakhs / year Capital cost of Heat Pump System = Rs. 150 lakhs   Payback 150 X 12 = 17 months 106

Advantage to the industry Reduced OPEX costs leading to accelerated payback within 18 months Possibility of reducing CAPEX costs in installed cooling loads 40% depreciation write off in 1st year of installation Accelerated payback ensures net positive cash inflows in finance mechanisms Reduction in fuel storage costs Reducing the carbon footprint Lesser pollution due to lowered emissions

Extended Advantage Extending the sunset of fossil fuels to buy time for alternate energies Reduced fossil fuel consumption resulting in lowered carbon pollution