What is assumed about this New York water-heating decision?
This is a hypothetical hotel in New York comparing gas water heating with an electric heat-pump system. There is no real customer, installed equipment, design proposal, supplier offer, or observed result. Assume the same useful monthly hot-water output is required in both cases: 30 million Btu, or 30 MMBtu. The quantity is invented, not a room-count consumption benchmark.
Assume the existing gas system delivers that output at 80% efficiency and the proposed heat-pump system has an effective coefficient of performance of 2.5. Both performance values are teaching assumptions for the entire modeled boundary. They are not ratings or verified seasonal results. A real comparison must identify which storage, recirculation, backup, and distribution losses are included in each system’s calculation.
An useful-output comparison holds the delivered thermal requirement constant while calculating different energy inputs. The bills hub explains the distinction between fuel quantities and cost components. Comparing gas-input energy directly with useful hot-water output would give inconsistent boundaries and distort the equipment decision.
Which state and technical sources support the review?
New York DPS’s clean-energy initiatives, reviewed October 12, 2026, identifies the NYS Clean Heat program and heat-pump technologies. This example assigns no incentive, program eligibility, or tax benefit. Obtain current utility and program confirmation for the actual customer, equipment, project scope, and timing before entering any credit in an investment model.
DOE’s small-business heat-pump water-heater guide is intended for commercial-building owners and facility managers considering water-heating electrification. It helps frame equipment and retrofit review; it does not supply the hypothetical hotel’s COP, useful load, or cost outcome. Competent design should establish capacity, recovery, source conditions, electrical connection, and operating controls.
Keep hot-water service and technical requirements fixed constraints. The purchasing worksheet does not prescribe temperatures, sanitation procedures, equipment settings, or storage capacity. A system meeting a monthly thermal total can still fail a short-period service requirement if recovery or storage is insufficient. Those questions need an engineering review beyond average energy arithmetic.
How does the assumed gas input reconcile?
Divide useful output by efficiency: 30 MMBtu ÷ 0.80 = 37.5 MMBtu of gas input. One therm contains 100,000 Btu, so 37,500,000 ÷ 100,000 = 375 therms. In Dth, the same quantity is 37.5 because one Dth is one million Btu. The two unit representations are consistent: 37.5 Dth × ten therms per Dth = 375 therms.
EIA’s Btu and conversion guidance provides the common energy-unit basis. Its electricity conversion of approximately 3,412 Btu per kWh is used below. Do not equate a cubic-foot gas quantity with therms without the account’s relevant heating-value treatment. This example starts directly with energy units to isolate equipment performance.
Assume the gas-input component is $1.20 per therm, an invented price rather than a New York tariff or current offer. The modeled gas cost is 375 × $1.20 = $450 monthly. Fixed charges, taxes, other riders, and remaining hotel gas uses are excluded. A conversion should not be credited with removing fixed account costs if the account remains active for another function.
How does the heat-pump electricity calculation work?
At the assumed COP of 2.5, electric input is 30,000,000 Btu ÷ 2.5 ÷ 3,412 Btu per kWh, or approximately 3,517.00 kWh. The useful thermal output expressed in kWh-equivalent is about 8,792.50, but purchased electricity is the smaller input after dividing by COP. The difference is transferred heat under the assumed system model, not unaccounted purchased energy.
Assume an electric energy component of $0.12 per kWh, also invented. Its modeled cost is approximately $422.04. Without another incremental component, that is $27.96 below the assumed gas case. This small difference is a scenario result, not expected project savings or a complete economic comparison. Rounding occurs only after the calculation.
| Hypothetical operating case | Useful output | Assumed performance | Purchased input | Energy component cost |
|---|---|---|---|---|
| Gas baseline | 30 MMBtu | 80% efficiency | 375 therms | $450.00 |
| Heat pump, base case | 30 MMBtu | COP 2.5 | 3,517.00 kWh | $422.04 |
| Heat pump, performance stress | 30 MMBtu | COP 1.8 | 4,884.72 kWh | $586.17 |
What changes when electrical demand is added?
Assume the heat pump adds 20 kW to the actual controlling billing interval and the relevant incremental demand component is $10 per kW-month. Both are invented inputs, and no actual tariff method is asserted. The added demand component is $200. Base heat-pump components then total $622.04, or $172.04 above the gas illustration.
In an alternate schedule scenario, assume approved storage and controls deliver the same thermal requirement without increasing the account’s billing determinant. Incremental demand is then zero and modeled components remain $422.04. The worksheet does not establish that such operation is feasible. Equipment power, available storage, recovery, guest hot-water timing, and the actual tariff must support it.
DOE’s utility-rate evaluation guidance supports checking the actual load profile and rate structure. An installed electric load is not automatically an equal increase in billing demand, and a schedule change may leave another peak controlling. Use verified intervals and the actual demand method rather than adding nameplate power indiscriminately.
How do performance and fuel-price stresses change the comparison?
At an assumed COP of 1.8, electricity becomes approximately 4,884.72 kWh for the same 30 MMBtu useful output. At $0.12, the energy component is $586.17. Add the assumed $200 demand component to obtain $786.17, or $336.17 above the gas baseline. This performance stress is not a prediction of winter COP or evidence about a particular installation.
For a separate fuel-price scenario, raise the invented gas component to $1.60 per therm while retaining 375 therms. Gas costs $600. The base heat-pump energy-only case is then $177.96 below gas, but the case with $200 added demand is $22.04 above it. A favorable fuel-price comparison can therefore change when the electrical determinant is included.
No probability is assigned to any scenario. The owner should evaluate the range using actual equipment evidence, costs, and risk tolerance. A monthly energy arithmetic advantage does not establish a payback period when capital, maintenance, replacement, design, and other operating effects are omitted.
What break-even component helps frame a real review?
At the base COP, the assumed gas cost of $450 divided by 3,517.00 kWh gives an electric energy-component threshold of approximately $0.12795 per kWh if incremental demand is zero. If $200 of demand is added, only $250 remains for energy before reaching the same $450 total. The threshold becomes about $0.07108 per kWh.
These are worksheet thresholds under the stated boundary, not offers or recommendations. They exclude differences in fixed costs and other charges. If the real system also changes space-conditioning requirements, include the effect through an engineering-supported model rather than assigning an automatic credit. Heat drawn from surrounding conditions can interact with other equipment and seasonal operation.
Broker compensation may be embedded or separate. For this illustration, the invented gas and electric energy components include any embedded fee, with no separate fee added. Retain actual disclosures and count compensation once when comparing supplier offers for the revised electricity and gas quantities. An equipment conversion does not automatically revise supply-volume obligations.
What should be verified before updating the hotel’s forecast?
- Establish useful hot-water requirements, short-period service needs, and system boundaries.
- Obtain competent design and supported efficiency or COP inputs for the actual installation.
- Reconcile Btu, Dth, therms, and purchased electricity consistently.
- Apply actual energy and demand components, including retained gas-account costs.
- Test performance, coincidence, fuel-price, and complete project-cost scenarios.
- Confirm any incentive separately, then verify commissioning, operation, contract changes, and invoices.
The Maine winter-gas example tests price and quantity together. The Connecticut laundry example tests schedule feasibility, while the New Jersey solar-storage example reconciles another behind-the-meter balance. Preserve this project’s useful-output boundary when combining those questions.