# Data centre heat loop

> Data centre heat loop is jouleWise's loop solution: a data centre's cooling return as the factory's heat source, under one contract.

Canonical: https://joulewise.com/solutions/data-centres  
Publisher: jouleWise Advisory Services Pvt Ltd, Noida, India · Spain  
Reviewed: 2026-10-08  
Status: company page

## In short

Low-cost green electricity delivered to the data centre's doorstep; heat pumps lifting the warm water from its cooling loop into hot water and low-pressure steam for the factory next door; one platform metering, dispatching and reporting both sites every fifteen minutes. One site dumps the heat; the other site buys it. A data centre turns almost every kWh its servers draw into low-grade heat in the cooling water, then pays again in chiller electricity and cooling-tower water to throw it away. A few hundred metres away, a factory burns gas, coal or diesel for hot water, washing, CIP, drying and jacket loops below 120 °C — its Scope 1 line, and the hardest carbon it has to cut.
## The opportunity

India's data-centre capacity is projected to grow to roughly 6.5–12 GW by 2030 (industry estimates). Each MW of IT load releases about a MW of heat, continuously. Today almost all of it goes to cooling towers, often next to industrial parks that burn fuel for the same temperature range.

### The data centre pays twice for the same kWh

- Draws electricity round the clock: a 10 MW IT hall is roughly 14 MW at the meter (PUE ~1.4), mostly grid electricity today.
- Almost every kWh the servers use ends up as low-grade heat in the cooling water.
- Then it pays again, in chiller electricity and cooling-tower water, to throw that heat into the air.
- Hyperscale and AI tenants ask for green electricity, low PUE and low water use, with evidence.

### The colocated factory burns fuel for low-temperature heat

- Burns PNG, coal, LPG or diesel in boilers for hot water, washing, CIP, drying and jacket loops, mostly below 120 °C.
- That fuel is its Scope 1 line: the hardest carbon to cut and the most exposed to price swings.
- CBAM, BRSR Core, CCTS and customer programmes now ask for metered evidence of the cut.
- Its heat load sits a few hundred metres from a 24×7 source of warm water.

## How it works

1. **Green electricity at the doorstep.** jouleWise builds the green portfolio to the data centre's flat 24×7 shape: ISTS and intrastate wind and solar hybrids, rooftop solar, BESS for the evening, and green-market purchase for the gaps. It handles open access approvals, ABT metering and SLDC scheduling.
2. **Capture the cooling-loop heat.** Warm water returning from the CRAHs, CDUs or condensers passes through an isolation plate heat exchanger. The data centre's water never leaves its own loop, and no change is made inside the white space.
3. **Lift it with heat pumps.** Industrial heat pumps take heat from that loop and deliver 70–90 °C hot water, or LP steam up to 120 °C. The cold side sends cooler water back to the data centre, so its chillers and towers do less work.
4. **Store, then deliver to the factory.** A hot-water store (about 400 m³ / 13 MWh-th in the example) is charged in the cheapest solar blocks and drawn on the factory's own shift pattern. Factory boilers move to standby and cover peaks or loads above 120 °C.
5. **Orchestrate on ergOS.** Every meter is on one screen: DC incomer, heat-pump electricity, heat across the boundary, store temperatures, factory header. ergOS forecasts 96 blocks and dispatches heat pumps and storage against price, cooling demand and process limits.
6. **Prove it on esgOS.** The same data becomes Scope 2 and green-attribute evidence for the data centre, Scope 1 fuel avoided for the factory, PUE and WUE trends, and BRSR Core, CBAM and customer disclosures. Each kWh is allocated across both companies at a metered boundary.

Why it works. The data centre has warm water it pays to get rid of, every hour of the year. The factory needs heat at a temperature a heat pump can reach. jouleWise green electricity is what makes that heat both cheap and close to zero-carbon.

## Dispatch rules on ergOS

- **Cooling comes first.** DC supply temperature is a hard limit. Heat pumps take only what the loop can give. Any surplus goes to the towers as usual.
- **Heat pumps follow price.** Output rises in the cheapest, greenest solar blocks and the surplus charges the thermal store.
- **The store covers the shifts.** Evening and night factory demand is met from the store, so the factory never waits on the sun.
- **BESS covers the evening.** Batteries charged on midday solar carry the evening peak, which raises the green share for the DC.
- **Boiler is the backup.** If the DC loop or the heat pump trips, the factory boiler fires automatically. Neither site is put at risk.

## The physics

A heat pump's efficiency (COP) depends on the lift: delivery temperature minus source temperature. Data-centre return water is a steady, warm, 24×7 source, much better than ambient air. The warmer the loop, the less electricity each kWh of factory heat needs.

- **Case A · conservative (air-cooled / chilled-water DC).** Loop return 20–30 °C; delivered ~80 °C; lift ~55 K; indicative COP ~3; per kWh of electricity 3 heat + 2 cool. Also cuts chiller electricity directly, since heat is taken out before the chillers.
- **Case B · lead case (liquid-cooled / AI racks).** Loop return 40–50 °C; delivered ~80 °C; lift ~35 K; indicative COP ~4–4.5; per kWh of electricity 4 heat + 3 cool. Direct-to-chip and rear-door loops run warm by design. That makes them the best heat source on any industrial site.

Energy balance at the base-case COP of 3.5: in, 1 kWh of electricity plus 2.5 kWh from the DC loop; out, 3.5 kWh of heat to the factory plus 2.5 kWh of cooling the DC no longer buys — about 6 kWh of useful heating and cooling per kWh.

Indicative COPs, consistent with the jouleWise lift table (≈5 at 30 K, ≈3.5 at 50 K, ≈2.5 at 70 K). LP steam up to 120 °C is possible at a lower COP (~2); hot-water loads are served first. Actual values come from metered loop temperatures and flows in the baseline.

## The loop in numbers (illustrative)

| Item | Value |
|---|---|
| Heat delivered to the factory | 40,000 MWh-th |
| Green electricity to heat pumps (COP 3.5) | 11,430 MWh |
| Heat taken out of the DC loop | 28,570 MWh-th |
| Factory fuel cost today (PNG boiler) | ₹24.9 Cr |
| Heat-pump energy cost (₹5.5/kWh green) | ₹6.3 Cr |
| Energy-cost saving, before capex and O&M | ~₹18.6 Cr |
| Scope 1 CO₂ avoided at the factory | ~8,800 t |
| DC chiller electricity avoided (Case A, chiller COP 5) | up to ~5.7 GWh |
| Cooling-tower evaporation avoided | ~40,000 m³ |

₹ per kWh of useful heat:

- Diesel (HSD) boiler: 10.59
- PNG-fired boiler: 6.22
- Heat pump on DISCOM electricity: 2.43
- Heat pump on DC loop, green open access: 1.57
- Heat pump in solar blocks + store: 1.14

Illustrative only, not an offer. 10 MW IT DC (PUE ~1.4); factory average demand 5 MWth at ~80 °C; COP 3.5; ~8,000 h/yr. PNG ₹55/SCM, 10.4 kWh/SCM, 85% boiler efficiency, 1.95 kg CO₂/SCM; HSD ₹90/L; DISCOM ₹8.5/kWh. Green electricity treated as zero-emission on a market basis. Water at ~1.5 L evaporated per kWh-th rejected; applies only where heat is rejected through wet towers. All values are replaced with metered site data in the baseline.

## What each side gets

### Data centre operator: Green, cooler, provable

- Low-cost green electricity at the incomer, with an RE share that holds up to hourly scrutiny.
- Part of the cooling load taken off chillers and towers, which means lower PUE, lower WUE and less make-up water.
- BESS on the evening peak and outages, so DGs run fewer hours.
- A heat-reuse story that hyperscale and AI tenants ask for, backed by metered numbers.

### Colocated factory: Green heat, no fuel

- Hot water and LP steam at a fraction of its fuel cost, priced per unit of heat.
- Scope 1 fuel emissions cut at source, with no new fuel supply contract to manage.
- Evidence for CBAM, BRSR Core, CCTS and customer supplier programmes.
- Boilers kept on standby as backup, with zero upfront capex under Heat as a Service.

### Both, together: One contract, one truth

- One accountable provider for electricity, heat, storage, metering and disclosure.
- A metered heat boundary, so both companies settle on the same 15-minute numbers.
- esgOS allocates electricity, heat and green attributes cleanly, so neither side double-counts carbon.
- A campus decarbonisation case that lenders and investors can underwrite.

## Engineered for uptime

- **Hydraulic isolation.** DC water, glycol and chemistry stay in the DC's loop. There is no shared fluid with the factory and no contamination path.
- **Heat rejection retained.** Existing heat rejection stays sized for full load. Heat recovery is a parallel sink, so Tier design and redundancy are unchanged.
- **Fail-safe bypass.** If the heat pump trips or the factory stops, valves return the loop to the towers within seconds. DC supply temperature is the controlling limit.
- **Factory continuity.** The thermal store gives hours of ride-through, and the existing boiler fires automatically for longer outages or loads above 120 °C.
- **Electricity resilience.** BESS carries short grid events and the evening peak. DGs stay for Tier certification and become the backup to the backup.
- **Metered boundary.** Flow and temperature are metered on both sides of the exchanger, so cooling credit, heat sold and carbon are settled on the same data.

## Why only a full stack can run one loop

| What the loop needs | Bought in pieces today | jouleWise |
|---|---|---|
| Green electricity to a 24×7 load | RE developer or trader | Open access, BESS, green market |
| DC cooling | Chiller OEM and facility team | Heat recovery as an extra sink |
| Factory heat | Boiler vendor and fuel supplier | Heat pumps, store, Heat as a Service |
| The interface between two companies | Nobody owns it | Metered boundary and one contract |
| Real-time sync of electricity and heat | Separate BMS and SCADA | ergOS, every 15 minutes |
| Carbon proof for both sites | ESG consultant, once a year | esgOS, continuously |

jouleWise's offer is the first in India to combine green electricity at the data centre's doorstep, heat pumps on its return water serving a colocated factory, and the metering, dispatch and disclosure layer, all from one provider under one contract.

Data-centre heat reuse operates abroad, mainly into district-heating networks in Northern Europe. The distinction claimed here is the integrated, single-provider model for an Indian DC and a colocated industrial heat user.

## How to engage

- **jouleWise designs, owns and operates the energy centre** (Recommended · Heat as a Service). The DC gets its return water cooled at no cost, and the factory pays per kWh of heat, priced below its current fuel cost. No upfront capex for either party.
- **RE-100 roadmap to PPA** (Advisory · green electricity). RE-100 roadmap, RfP and reverse auction, PPA, open access approvals and ABT metering for the DC, and the factory where useful.
- **Per-plant subscription** (SaaS · ergOS + esgOS). Metering, dispatch and disclosure across both sites.
- **Owner holds the asset** (Heat Advisory). Engineering route from boiler to heat pump with the owner holding the asset: heat audit, sizing, EPC oversight, commissioning.

| When | Step |
|---|---|
| Wk 1–4 | Joint baseline. DC loop temperatures and flows, PUE and water data, factory heat map with portable heat meters, electricity bills and 15-minute data. |
| Wk 4–8 | Design and business case. Heat-pump and store sizing, hydraulic interface, green electricity portfolio, tripartite heat agreement. |
| ~3 months | Electricity live. Open access contracted and approved. Meters and loggers on ergOS. |
| 6–12 months | Energy centre live. Commissioned with the DC on bypass first, then heat recovery stepped up block by block. |
| Ongoing | Operate and disclose. ergOS runs both sites and esgOS reports for both, with an audit trail. |

Timelines indicative. They depend on state approvals, equipment lead times and DC change-control windows.

Source deck: https://joulewise.com/downloads/joulewise-data-centre-heat-loop.pdf
## The problem

One site dumps the heat; the other site buys it. A data centre turns almost every kWh its servers draw into low-grade heat in the cooling water, then pays again in chiller electricity and cooling-tower water to throw it away. A few hundred metres away, a factory burns gas, coal or diesel for hot water, washing, CIP, drying and jacket loops below 120 °C — its Scope 1 line, and the hardest carbon it has to cut.

## What we do

- **Green electricity at the doorstep.** A portfolio built to the data centre's flat 24×7 shape: ISTS and intrastate wind and solar hybrids, rooftop solar, BESS for the evening and green-market purchase for the gaps, with open access approvals, ABT metering and SLDC scheduling handled.
- **Capture and lift.** Warm return water passes an isolation plate heat exchanger; industrial heat pumps lift it to 70–90 °C hot water or LP steam to 120 °C and send cooler water back, so chillers and towers do less work.
- **Store and deliver.** A hot-water store charged in the cheapest solar blocks and drawn on the factory's shift pattern; boilers move to standby for peaks and the duties above 120 °C.
- **Orchestrate and prove.** ergOS runs both sites on one screen every fifteen minutes; esgOS allocates electricity, heat and green attributes across both companies at a metered boundary.

## Where it stops

- **Uptime is never traded.** The energy centre is a parallel heat sink behind hydraulic isolation and an automatic bypass. Towers and dry coolers stay N+1, Tier design is unchanged, and the DC supply temperature is the controlling limit.
- **The loop sets the ceiling.** Heat pumps take only what the loop can give. Hot-water loads are served first; LP steam to 120 °C comes at a lower COP; anything hotter stays on fuel.
- **Illustrative until metered.** COPs, savings and water figures are indicative and depend on cooling architecture, loop temperatures and the state's regulation. The joint baseline replaces every one of them with site data.

## What we need to start

- A year of DC electricity bills and cooling-loop temperatures and flows
- PUE and water data
- The factory's fuel and steam records and heat map
- Fifteen-minute data where it exists
- The two parties' willingness to settle at a metered boundary

## What drives the economics

- Loop return temperature, which sets the lift and the COP
- The price of the green electricity the heat pumps run on
- The factory's fuel cost per kWh of useful heat
- Hours of coincident heat demand
- Chiller electricity and cooling-tower water the DC no longer spends
## Facts

- Green electricity at the doorstep: A portfolio built to the data centre's flat 24×7 shape: ISTS and intrastate wind and solar hybrids, rooftop solar, BESS for the evening and green-market purchase for the gaps, with open access approvals, ABT metering and SLDC scheduling handled.
- Capture and lift: Warm return water passes an isolation plate heat exchanger; industrial heat pumps lift it to 70–90 °C hot water or LP steam to 120 °C and send cooler water back, so chillers and towers do less work.
- Store and deliver: A hot-water store charged in the cheapest solar blocks and drawn on the factory's shift pattern; boilers move to standby for peaks and the duties above 120 °C.
- Orchestrate and prove: ergOS runs both sites on one screen every fifteen minutes; esgOS allocates electricity, heat and green attributes across both companies at a metered boundary.

## Assumptions and limits

- Uptime is never traded. The energy centre is a parallel heat sink behind hydraulic isolation and an automatic bypass. Towers and dry coolers stay N+1, Tier design is unchanged, and the DC supply temperature is the controlling limit.
- The loop sets the ceiling. Heat pumps take only what the loop can give. Hot-water loads are served first; LP steam to 120 °C comes at a lower COP; anything hotter stays on fuel.
- Illustrative until metered. COPs, savings and water figures are indicative and depend on cooling architecture, loop temperatures and the state's regulation. The joint baseline replaces every one of them with site data.

## Questions and answers

**Does the data centre's water go to the factory?**  
No. An isolation plate heat exchanger keeps the DC's water, glycol and chemistry in its own loop. There is no shared fluid and no contamination path.

**What happens if the heat pump trips?**  
An automatic three-way bypass returns the loop to the towers within seconds; the factory's thermal store gives hours of ride-through and its boiler fires automatically for longer outages.

**Who pays for the energy centre?**  
Under the recommended Heat as a Service model, jouleWise designs, owns and operates it. The DC gets its return water cooled at no cost and the factory pays per kWh of heat, below its current fuel cost.

**How much does the factory save?**  
In the deck's illustrative 10 MW IT, 5 MWth example, about ₹18.6 Cr a year in energy cost before capex and O&M, with about 8,800 t of Scope 1 CO₂ avoided. The Data Centre Loop Studio recomputes this for other sizes and temperatures.

## Related

- [Size the loop in Data Centre Loop Studio](https://joulewise.com/studios/dc-loop)
- [How you buy it](https://joulewise.com/engagement)

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jouleWise · https://joulewise.com/ · sales@joulewise.com · +91 84483 22771