Using Waste Heat as a Utility - Star Refrigeration Blog


Cooling and Heating as a Utility


Dave Pearson

Director of Innovation SRE


Ask most members of the public what utilities they use and most will say gas and electricity. Business users are probably in the same boat, perhaps adding water which will be metered. And this is the key thing; if there's a meter and you pay for it it's on your radar.

Increasingly, businesses are thinking more in terms of "the specific use" or "the outcome." This is largely due to a desire to better understand costs, and the first step of this is to sub meter. So, good businesses will be living the maxim of "if you don't measure it, you can't manage it."

  • Star's Neatpump plantroom in Drammen

Measuring the final "outcome" from electricity and gas

By far, the most commonly used utility is electricity; everything from lighting to photocopiers to telephones to PCs. In all but a very few exceptions, businesses that have a requirement for cooling, especially process cooling, will spend most of their electricity on this. Over 50% of electrical spend for cooling wouldn't be unusual. The electricity is used to run refrigeration equipment to capture the unwanted heat, move it to an outside location and chuck it away.

Less common by usage is gas. Aside from cooking and niche chemical processes, gas will be used mostly for heating and perhaps drying. In these cases, the gas is burned to make hot air, hot water or steam and either used at that location or the secondary media moved and used in that form or transformed again into hot air or hot water.

The curious and indeed difficult thing is how to measure the quantity of the "final outcome." This is especially tricky if it is warm air and, to a lesser extent, steam. Measuring warm water is simple. Flow rate and temperature difference will give an instantaneous value in kW and this consumed over a period of 1 hour would be in kWh. An identical treatment can be made of cooling if it is a fluid.

So, as we desire to understand our utility bills - not only are they topical but they are increasingly costly, often equal in value to retained profit - then sub metering and defining our utility far closer to the point of consumption is viable and, more importantly, extremely valuable.

If we set a target of knowing how much of each "end utility" we use at each location, we can begin to claim to be measuring the system.

At the end of the day, does your business sell a product or does it sell the utility(s) you consumed to achieve that product? You can't put 30% less meat into a pie and not notice the quality drop, but you could make the pie using 30% less utilities.

The excess consumption is, in effect, throwing away your profit margin. You get absolutely zero credit, unlike gifting extra product where at least you'd get a feel good factor for the baker's dozen.

Harvest your waste or your local heat source to increase your profits

The value comes not from knowing how many kWh (kilowatt hours) were used at each location on any specific day, or indeed at what temperature (i.e. was cooling used at -5°C or heating used at 60°C) but from then - armed with a 4 dimensional energy map - being able to draw up a plan to use less.

The simplest way to use less is... to use less. If a process is being heated too warm or at the wrong time of day, obliterate that small portion of the total bill. If one utility is being consumed to balance another (heating and cooling acting on the same space) then obliterate it.

However armed with this intimate knowledge of just where the pounds, Euros or dollars are being sucked out the profit margin and into the process, we can perhaps achieve a virtuous result by another method.

  • Star Neatpump

Neatpumps use waste from cooling to deliver heating for industrial processes

An animation that describes how a combined heating and cooling process in a factory can save money and carbon. The Neatpump by Star Refrigeration is an ammonia heat pump that uses the Vilter single screw compressor and delivers significant savings using just a little bit of joined up energy thinking.

Why do we typically burn gas to make stuff warm, then burn electricity to cool it back down again by stripping it of heat, and then throw that heat away? What if we could capture that heat and re-use it?

Then, we would change the rules and re-take control. This is far wiser than thinking we simply need to switch suppliers.

Refrigeration systems are essentially "energy transporters" - but refrigeration does sound far "cooler." They grab excess heat in one place and move it to another, usually warmer place, and chuck it away.

Heat pumps are not reverse fridges. They still move heat from the cool place and deliver it in the warm place. It's just that we now have a profound interest in the warm place.

We can deliver that heat at higher temperatures (fridges usually dump heat around 30°C) and make it useful. 60°C is warm enough for heating buildings and creating hot water. 90°C heat is also viable and can be used in industrial processes.

Making steam might well be technically possible, but it always comes back to the commercial cost vs a simpler solution of burning something. Gas is about 1/3rd of the cost of electricity, so a heat pump that can deliver 3x as much heat as it consumes electricity is the same operating cost as burning gas.

The closer source and demand temperatures are the less work is required to move the heat from the low place to the high place, to the point where none is required at all because no temperature lift or work was done.

Therefore, find out where you use heat, what form you use it in, when during the day you use it and at what temperature. Use this four dimensional approach and then do the same for the cooling and the waste heat from the cooling. Finally, overlay these maps and maybe instead of burning stuff for heat you could use your own waste or harvest a local source. It doesn't need to be "waste heat," it just needs to be easy to get and plentiful - a river, for example.

Related Case Studies

  • Drammen Neatpump

    UK firm Star Renewable Energy has launched a groundbreaking sustainable heating system which is heating homes and businesses across an entire city in Norway.

    Heat pumps are becoming increasingly popular across Europe as the heat they deliver far exceeds the energy they consume. District heating sees heat generated in a centralised location distributed for residential and commercial heating.

    By 2009, the Norwegian city of Drammen's population had grown to such a degree that its existing district heating system could not cope. While researching ways to expand its capacity, the city's heating company Drammen Fjernvarme, led by Jon Ivar Bakk, discovered the water temperature in the fjord was ideal for heat pumps.

    Star Renewable Energy stood out amongst other bidders during the tender process, despite having no prior experience of water source heat pumps. The Glasgow based company is best known for providing refrigeration systems to some of the UK's biggest retailers, including Tesco and ASDA. As Director Dave Pearson says, "We were the new kids on the block, but we've always had a reputation for pushing boundaries."

    District heat pumps already exist in Scandinavia and across Eastern and Central Europe, providing higher efficiencies than traditional localised boilers. However, many of these first generation systems rely on hydrofluorocarbon (HFC) refrigerants, which are thousands of times more potent as global warming gases than carbon dioxide when emitted to the atmosphere. HFCs are currently being phased out by the EU under the Montreal Protocol.

    Hence, Star's selling point was simple - while other companies were using HFCs as the coolant, Star proposed using ammonia, a naturally occurring refrigerant with zero ozone depletion potential. Ammonia has never been used in a high temperature heat pump allocation of this type. Electricity for the Drammen system is provided by hydropower, making the Neatpump's carbon emissions virtually zero.

    Star's Neatpump is a renewable energy heat pump that extracts heat from seawater, air or any industrial waste stream, such as air conditioning or large scale cooling processes. This waste heat is captured, compressed, boosted and recycled to provide hot water at up to 90°C for heating buildings on a massive scale. The project was completed in January 2011, and has since delivered over 15MW of heat for the Drammen community of 60,000 people. It is the world's largest district-wide natural heat pump system.

    And if it works in Drammen, it can work anywhere where there is a constant supply of water, standing or flowing.

    In the UK, Star is already working with local housing associations in Glasgow, and is also speaking with a dozen city councils, including Newcastle, Durham, Manchester and Stoke. It is also working on projects in Zurich and the south of France, and bidding for a system in Belgrade. The potential is huge - for example, the Thames could generate 1.25GW of capacity, enough to heat 500,000 homes.

    Dave Pearson says: "Systems such as the Neatpump could literally revolutionise the way we heat factories, hospitals, office buildings, data centres, even entire communities across the globe. The technology behind it is so advanced that it can even be configured to deliver district wide air conditioning, with waste heat providing the energy to drive desalination processes for producing fresh drinking water."

    He adds; "At present, a shocking amount of heat generated through cooling processes worldwide is simply discarded as waste to the atmosphere. Organisations could now be recycling waste heat from their process, air conditioning and IT cooling systems and boosting it for use in their own and neighbouring buildings."

    Star's heat pumps have been providing Drammen district heating with 85% of the hot water needed to heat the city. "We are very happy with it," says Mr Bakk. Having already paid for itself, and with annual savings of around 2m a year and 1.5m tonnes of carbon - the equivalent of taking more than 300,000 cars off the road for a year - it's not hard to see why.

    Star has invested heavily in zero carbon technology and continues to develop new products to provide energy conscious systems for the benefit of customers and the environment.

    Click here to view the full related article on the BBC website.

    Star focuses on the design, manufacture, installation, commissioning and aftercare of industrial refrigeration and HVAC (heating, ventilation and air conditioning) systems.

    For more information, phone Star Refrigeration on 0141 638 7916, email or visit  Star Refrigeration, Thornliebank Industrial Estate, Glasgow G46 8JW.

  • Norwegian Army

    UK firm Star Refrigeration has designed a groundbreaking renewable energy heat pump system to serve a military base in Norway.

    The Glasgow-based cooling and heating specialist, with Norwegian refrigeration partner Norsk Kulde, has just installed the Neatpump system at the Ramsund Naval Base. Located in the northern county of Troms, the coastal facility is used for Norwegian Army and Royal Norwegian Navy vessel repairs and is also a Special Forces base.

    Star’s Neatpump is an innovative ammonia heat pump plant that extracts heat from seawater in Ramsund’s harbour. A glycol loop submerged in the harbour helps provide hot water and heating to all buildings on the base.

    Neatpump has replaced an ageing heat pump system at the Ramsund base. The previous plant, which operated on synthetic refrigerant R134a, suffered a system failure following less than ten years’ service. The Norwegian Army was looking to replace the existing plant with an environmentally conscious, energy saving heat pump system, with a robust, low maintenance design.

    Unlike many first generation heat pump systems, Star’s Neatpump does not require any synthetic global warming gases (HFCs). It operates using a low charge of ammonia, a naturally occurring refrigerant that has zero ozone depletion potential.

    Ramsund’s Neatpump was built at Star’s Glasgow manufacturing facility and was shipped as a complete packaged unit, ready for installation in an existing plant room at the military base. The plant has a 600kW capacity and a COP (Coefficient of Performance) of 2.7, heating water to temperatures between 60 and 68 degrees Celsius.

    Commenting on the Ramsund project, Kenneth Hoffmann, Star’s Sales Manager – Heating, says: “Energy efficiency and build quality were key to securing this contract. Neatpump’s advanced compressor technology and ultra low maintenance design ensures over 20 years of environmentally conscious service.”

    Kenneth Hoffmann adds: “This is our second Neatpump installation in Norway, working in partnership with Norsk Kulde. Our 15MW district heating system on the Drammen Fjord near Oslo is providing hot water and heating to over 60,000 homes and businesses.”

    Star’s Neatpump is a renewable energy heat pump that extracts heat from seawater, air or any industrial waste stream, such as air conditioning or large scale cooling processes. This waste heat is captured, compressed, boosted and recycled to provide hot water at up to 90°C.

    The Vilter single screw compressor is at the heart of Neatpump. The unique compressor design has balanced pressure across the central rotor, ensuring long life, high reliability and low maintenance. Neatpump is designed to provide over 20 years service without the costly maintenance work associated with other compressor types.

    The high efficiency Neatpump is available with capacities ranging from 300kW to 8000kW. The system can be designed to cool both water and secondary fluids including glycol, making it suitable for a variety of applications including process cooling and heating, AC with heating, steam raising and district cooling, heating and desalination.

    Ideal for both new projects and retrofits, Star’s Neatpump can be commissioned and charged prior to delivery, reducing site installation and commissioning time.

    A world leader in cooling system innovation, Star has developed a range of heat pump solutions to meet the needs of end users in the building services and industrial sectors. As an environmentally conscious supplier, Star’s heat pump solutions typically use natural refrigerants, such as ammonia and carbon dioxide for high efficiency heat generation.

    When it comes to designing energy efficient cooling and heating systems, Star is a natural innovator. Star works with strategic partners across the globe to deliver low carbon, cost saving solutions.