Cogeneration
A building with continuous
heat demand can run its
own generation. Here's
how do it.
A hotel general manager and the operations director of a fitness club share a problem most industrial plants don’t have: the heat they buy is part of the experience their customers are paying for. A lukewarm pool or a shower that runs cold during the morning peak is a service failure, not a billing problem.
That puts CHP (Combined Heat and Power or Cogeneration) in these settings on slightly different footing from CHP in a factory. The plant cuts the energy bill, as it would anywhere, but it also affects the quality and continuity of something the customer notices directly.
In a factory or a wastewater plant, heat is a utility. It supports a process; the customer doesn’t see it. In a hotel, a hostel, a spa, a fitness centre, a public swimming pool, heat is something the customer experiences directly. A pool that isn’t at the right temperature when the first guest arrives in the morning is a problem the front desk will hear about within minutes. The same goes for a shower that turns lukewarm during the morning peak, or for a wellness area where the warmth feels off.
It matters for two reasons, and both point toward CHP.
The first is the one any operator already knows: heat is a major running cost, often the largest after labour and food. Anything that produces the same heat with less fuel goes straight to the operating margin. A well-sized CHP plant uses one fuel to produce both electricity and heat, recovering the heat that a conventional power station and a separate boiler would waste.
The second is less obvious, and matters more in daily operations. A CHP plant produces its heat continuously, on site, sized to the demand of the building. The hot water it generates doesn’t wait for a boiler to fire up at peak times or to recover after an unexpected load. It’s a steadier source of thermal supply than the conventional setup, which is what guests notice when something goes wrong.
Operators often underestimate how much heat their building consumes, because the consumption is split across many points and never appears on a single bill. Listing them puts the scale in proportion.
Domestic hot water. Showers and sinks across all rooms, plus kitchen use. The single biggest constant in any accommodation site. Demand peaks in the morning and the evening, never falls to zero, and stays roughly the same in summer as in winter, because people shower as often in August as in February and rooms keep filling. The largest hotels run hot water systems that effectively never stop.
Pool and spa. Pools lose heat continuously to evaporation, basin conduction and the ventilation that pool halls require by regulation. They lose it in winter and in summer, day and night. A heated pool is one of the most constant heat loads any building can have. Spa pools, hot tubs, saunas and steam rooms add smaller but equally continuous loads.
In-house laundry. Hotels above a certain size operate their own laundry, and laundry is one of the heaviest hot water users in the building. The towels and linen of a single full-service property can require tens of thousands of litres of hot water a day. Whether laundry is in-house or outsourced shifts the site’s energy profile significantly.
Space heating. The most variable load, and the only one that’s truly seasonal in most climates. It dominates the bill from October to April, then drops sharply. It’s the load most operators have in mind when they say “we don’t need heat in summer”, but as the list above shows, it’s only one piece.
Kitchen. Cooking equipment and dishwashing, plus general kitchen sanitation. Less continuous than hot water or pool, but a meaningful share, especially for restaurants and banquet operations.
What looks like five separate items is in fact one overall heat profile: a high baseload that runs year-round across hot water, pool, laundry and kitchen, with seasonal heating layered on top. That total is the kind of demand a CHP plant is built to match.
The objection most operators raise first is seasonal. Most of the heat load disappears in summer, so why pay for a CHP plant that sits idle for four months?
The objection assumes that space heating is the whole story. As the inventory above shows, hot water, pool losses, laundry and kitchen continue at roughly the same level all year. In hotels that stay open through the summer, which in most markets is now most hotels, the only load that actually drops is space heating itself, and that drop is partly offset by the air conditioning load on the electrical side, which a CHP plant supplies with the same electricity it generates in winter.
What changes a CHP business case in a leisure or hospitality setting is not whether the site needs heat in summer, but whether the site has a continuous baseload to anchor the plant. For most hotels with a pool or a wellness area, and for most fitness clubs of any size, that baseload exists. The plant runs against it. The seasonal heating component is the variable bonus.
A separate technology, called trigeneration, takes the principle one step further by turning some of the recovered heat into cooling through an absorption chiller, which can make sense for sites with strong summer cooling demand. Even before trigeneration, the year-round heat demand of a hospitality or leisure site is usually enough to make CHP work.
A small fitness and wellness centre in northern Italy installed one of our single micro-CHP unit rated at 20 kW of electrical output. The site has a pool, a sauna, changing rooms with constant shower use, and a heated training area. The unit produces electricity for the operation and recovers heat for the hot water and pool circuits. Because the wellness demand runs almost without interruption (the centre is open seven days a week), the plant operates close to full capacity for most of the year, and the energy bills dropped by a meaningful share without changing anything the members notice.
A second example: a hospitality site in central Milan installed two of our micro-CHP units producing about 40 kW of electricity and 80 kW of thermal output together. In a dense urban context, the value goes beyond the bill. The site is less exposed to grid disturbances. Hot water supply is decoupled from boiler scheduling. The carbon footprint, which is now part of how groups and investors evaluate the brand, improves measurably.
These are representative cases of what a properly sized micro-CHP installation looks like in this sector. The size of the unit follows the site: a small wellness centre needs less than a 200-room hotel, which needs less than a resort with multiple pools and a major laundry. What stays the same is the principle: a site with continuous heat demand can produce that heat with less fuel, more reliably, on its own premises.
For an operations director or a general manager weighing this up, three points follow.
The first is the simplest. The heat the CHP plant produces is the same heat the building needs anyway. The investment isn’t buying a new utility, only a more efficient way to run one the building already runs.
Then there’s reliability. A site that produces its own thermal supply through a properly maintained CHP unit is less exposed to the kind of failures that end up on review sites and in guest complaints.
And finally, the energy efficiency reports that brands, owners and ESG frameworks now require show measurable improvements. The numbers stand up to external audit because they come from a single, monitored plant rather than from a patchwork of disconnected systems.
The right next step is the same as for any site considering CHP. The numbers depend on the demand profile, the operating hours and local energy prices, which a feasibility assessment exists to measure.
There’s no standard size, because there’s no standard hotel. A small wellness centre with a single pool and a sauna may be served by a micro-CHP unit of around 20 kW of electrical output, while a large hotel with a pool, an in-house laundry and a busy kitchen can justify several hundred kW. The right size comes from the building’s continuous heat demand, not from its star rating or its room count.
Yes, and pools are among the strongest applications. A heated pool loses energy continuously to evaporation, basin conduction and ventilation, which means it has a steady, year-round heat demand that suits a CHP plant well. The recovered heat from the engine is transferred to the pool circuit through standard heat exchangers, and the plant runs close to full capacity for the hours the pool is heated.
A CHP plant produces hot water on site, sized to the building’s demand. The supply doesn’t depend on a boiler that might fail to keep up under peak load, or on a grid disturbance that affects everything at once. For sites where hot water continuity is a service issue, not just a utility issue, that on-site source makes a measurable difference to reliability.
No. Micro-CHP units start from a few kW of electrical output, sized for small accommodation sites, condominiums, fitness centres and similar buildings. What matters is the heat profile, not the number of rooms. A small hotel with a heated pool and regular hot water use can be a better candidate than a much larger property without continuous heat demand.
Yes. A CHP plant reduces the amount of primary energy a site burns to produce the same amount of heat and electricity, which translates into a lower carbon footprint that’s straightforward to document. The metering on a modern CHP unit produces continuous, audit-ready data on fuel use, electricity generated and heat recovered, which fits the way most ESG frameworks expect to see energy efficiency reported.
