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TOTEM engine for Combined Heat and Power (CHP).

What is a Micro CHP engine? And How Does CHP work?

Onsite cogeneration of electricity with heat reclaim by Combined Heat and Power, or CHP units, is one of the most effective ways of reducing costs by simultaneously powering and heating a building from a single gas-powered engine.

As gas supply remains on a par with or slightly cheaper than grid-supplied electricity, and because Combined Heat and Power units secure ‘free / waste heat’ as part of that power generation process less gas overall is required for the heating of the building. So there are two opportunities to reduce operational costs.

The micro-CHP form factor that we deploy in the TOTEM series of CHP units was originally conceived and brought to market in the late 1970s. Subsequently, the design has evolved and improved, incorporating the latest engineering practices and expertise from the automotive industry to ensure the design is optimised to meet the real-world needs of a building project.

The TOTEM m-CHP internal combustion engine is a product of the automotive expertise of Fiat Chrysler Automobiles’ (FCA). The continuous development over 50 years, gives the current gas-driven 1.4L Fiat Fire engine an astounding reliability rate of 99.6% over 100,000 units per year.

The Engine Control Unit (ECU), high-efficiency catalytic converter and fine-tuning for the engine’s stationary parameters is provided by Magneti Marelli, a name which will be familiar to fans of Formula One racing. It is the ECU and catalytic converter that which deliver TOTEM’s ultra-low NOₓ and CO emissions. This is particularly important for urban building projects where NOₓ (a combination of NO and NO2) is seen increasingly as a major factor in air pollution which can be extremely harmful to people. As Combined Heat and Power localises energy production, it is critical that the use of the technology addresses and significantly reduces NOₓ generation. NOₓ emissions from a TOTEM unit are less than 40 mg/kWh of electricity output, but once you take the heat output into account, which is considered a waste product, TOTEM becomes effectively NOₓ free.

TOTEM achieves ultra-low emissions rates –  that are less than 10% of most micro-cogeneration units available on the market –  through the close manufacturing relationships, of Fiat, Magneti Marelli, Asja and Adveco which has driven the adoption of micro-CHP in the UK through unique technology and service support. For this work, Adveco has been recently awarded a Frost & Sullivan Technology Innovation Leadership Award for developing commercial micro-CHP in Europe.

TOTEM stands out with its complete, highly compact system in a box configuration, a design-driven by the decision to directly couple the engine to the generator, which is capable of delivering electrical outputs from 10 to 50 kW, and then closely integrate the other components, especially the condensing heat exchangers.

A building’s central heating water is heated directly in two stainless steel shell and tube heat exchangers and a water to water stainless steel plate heat exchanger transferring heat from the engine coolant (used to cool the engine, oil, and generator water jacket) and from the first stage exhaust. By reclaiming heat from every available source, TOTEM micro CHP units achieve a thermal efficiency of 65% or higher depending on the return water temperature. The TOTEM will condensate when the return water temperature is less than 50°C without the need for an additional flue heat exchanger.

Based on today’s fuel costs electricity output from the co-generator will be at a similar cost to electricity from the grid, however for each kWh of electricity generated approximately 2.5 kWh of free, high-grade heat will be recovered. With ultra-low emissions, micro CHP offers a real option, especially when combined in an application that blends renewables to provide a cost-effective and future-proof method for providing the power and heating needs for commercial projects.

Berry Court care home plant room installation.

The Cogeneration Gap – Part 3 Caring for the Environment

We have considered the reasons for implementing m-CHP in new builds and upgrading care homes. In this third and final blog in the series, we consider one last deciding factor, the environmental impact of local cogeneration…

The carbon savings have long been an advantage of Combined Heat and Power (CHP), and can still be achieved, but that is changing because grid-supplied electricity is getting much cleaner. There has been a strong downward trend in emissions from electricity production since 2014, due to the increases in wind and solar power and the closure of coal-fired power stations. But on average, CHP provides a carbon benefit over the year, though the actual intensity fluctuates both seasonally and daily. On most days where carbon intensity is more than 188g/kWh CHP will provide a benefit. CHP will be carbon advantageous at some times of the day and not at others, but looking at the average carbon intensity of electricity generation from 2013-2017 even in the summer months when demand falls, the carbon intensity never fell below 200g/kWh, so CHP was always beneficial in this period in terms of carbon savings. Carbon intensity of the grid is higher when it is dark and cold, and CHP requires a thermal load to operate so naturally aligns itself with the higher carbon intensity when it provides greatest impact and savings.

In the future smart controls will adapt CHP run times to ensure it operates when it is most carbon advantageous.  For a CHP that runs for 14 hours per day, for example, the smart controls will ensure that the 10 hours when it does not operate align with the clean grid periods and not when the carbon intensity is the highest.

Even so, we recognise that the value of carbon savings with CHP will continue to reduce in comparison to previous years. Instead, attention is now turning to Nitrogen Oxides (NOX) savings. A by-product of the combustion of hydrocarbon fuels, NOX are a major contributing factor to poor air quality, the most toxicologically significant being a combination of nitric oxide (NO) and nitrogen dioxide (NO₂). It can cause lung irritation and respiratory infections as well as being linked to cancer, asthma, strokes, and heart disease. The Royal College of Physicians believes it directly leads to as many as 40,000 deaths each year. This has led to widespread recognition that more needs to be done to address NOX emissions and the care sector needs to be seen to be addressing emissions that are a by-product of its activities.

Although all CHP with a catalytic converter is cleaner than the grid, taking in to account electrical efficiency, the wider CHP industry, as an average, has the same NOx emissions as large scale power generation. The downside for CHP has been that carbon-based power generation historically was located outside of major urban areas, but the drive for low carbon buildings is bringing even more potential emissions into our cities. Most CHP are likely to have a slight positive impact on air quality nationwide, but because those installations will typically be in urban/residential areas that CHP will have a negative impact.

Therefore, localised NOX emissions from ‘dirty’ cogeneration is becoming a concern. Where CHP is used to offset condensing boiler run hours, if the CHP is dirtier than the condensing boiler then the local emissions are worsened. Despite air pollution and NOX mainly arising from road traffic – half of current NO­X pollution in major urban areas is attributed to vehicles – emissions from decentralised energy production are now being seen as a contributing factor. It is therefore of great importance that the NOX emissions from new CHP units are lower than condensing boilers if they are to have a positive effect.

Our own assessment of cited NO­X emissions from CHP manufacturers shows wildly fluctuating numbers, ranging from 64 mg/kWh to a highly concerning 596 mg/kwh, and older units were far worse. Consider the 2018 EcoDesign limit for CHP is 240mg/kWh! And I would argue that this number is now far too high given the changing attitude to, and awareness of the dangers of NO­X emissions.

Despite heat recovered by the CHP being considered NOX neutral, it is vitally important to recognise that there is a considerable difference between ‘dirty’ CHP and the latest generation of low-NO X CHP. One such class of low-NO X appliance are the micro or m-CHP units, where we can cite emissions levels as low as 11mg/kWh. For a unit of 20kW electrical output, with a gas input of 70kW, in a situation with an average annual run time of 6,500 hours for a standard application such as a care home, the yearly NOX emission from a ’dirty’ CHP will be 109.2kg/year, compared to 4.55kg/year for the latest generation of m-CHP. And remember, this option is also improving local air quality because the m-CHP is used to offset the run hours of a condensing boiler which at emissions over 30 mg/kWh is dirty compared to the CHP.

Conclusion

Comparing CHP with other local energy generation technologies, today we can still show that it has lower running costs than a heat pump, plus has both higher savings and an easier install than PV. Without doubt, a CHP can provide useful energy cost savings for a building, so it always makes sense to run existing CHP, and makes sense to purchase for the right type of building.

Mid to high occupancy residential care homes are particularly apt and upgrading to CHP in these facilities will provide a good payback period and be a solid investment over the decade, so long as a guaranteed maintenance schedule is put in place.

Finally, selecting the right CHP can provide carbon savings and more importantly, as we look to the future, can help improve local air quality for a building.

At the end of the day, the building and its use should drive the decision making, but for the care home, perhaps the greatest advantage of all is the assurance that residents will have a continuity of comfort through the provision of heating and hot water. It is in this role that m-CHP delivers a business-critical need in the care home environment.

TOTEM T20 CHP unit (Combined Heat and Power unti) in a residential care home.

The Cogeneration Gap – Part 2 Embracing CHP

In the first part of this short blog series on the application of micro-CHP within residential care homes Adveco explained why CHP (Combined Heat and Power) is often chosen for new builds. In this second part, we turn our attention to why you would upgrade existing facilities to m-CHP…

The cost of deploying CHP within care homes is, without doubt, the deciding factor for the majority of managers. When calculating the operational cost savings, we need to take the cost of the offset electricity and thermal energy, and deduct the costs of the energy coming in, in other words, the price of the gas, and the maintenance costs. The other key input is the number of run hours per year that the CHP appliance will operate.

A CHP is very different to a boiler, which other than an annual service you would typically tend to forget about. Inside the CHP casing is a gas-powered automobile engine, with high stressed moving parts that will require necessary repairs over time that could reduce savings. So, you need to be aware of the ongoing investment needed when operating CHP to support regular pay as you go maintenance and repair. Once the cost of maintenance is factored in, the operating costs can be determined based on electricity and gas prices.

To understand what these operational costs look like, I am going to cite current figures based on the installation of a TOTEM T25 micro-CHP unit. From our experience, these are typically the size of a unit a larger care home will install. Firstly, being gas-powered, the CHP is a far better option when the cost of gas is less than electric, which has been the trend since 2015. Currently, based on medium non-domestic rates, a T25 will save £1.50 per hour that it runs. Let’s consider the expectation on run hours per year, many CHP units that have gone in will run relatively short hours per year just to increase the efficiency of the building to meet carbon requirements. Looking at the demands of the London Plan, for example, 2,500 run hours may be sufficient to meet the additional carbon savings demanded. At that lower run rate, the CHP is still going to save £3,750 savings per year.

This may not be enough to provide a true payback, but are interesting savings in an inherited, new building, where the cost of the CHP is part of the cost of the building and does not have to be proven to pay back. The decision is only to run it and save £3,750, or not and save nothing.

Upgrading to CHP

But what if you want to upgrade your plant room, when is right to Include CHP? The technology offers a number of advantages, the micro-CHP is especially easier to install, passing through a standard 60cm doorframe and able to be installed internally, avoiding the need for external space or rooftop placement which would be needed for say solar photovoltaics (PV) which is another common choice for onsite energy generation. CHP also offers better payback than Air Source Heat Pumps (ASHP) and with inclusion in the Government’s new SEG payments, you can profit from additional energy generated by selling it back to the grid from your CHP at a guaranteed tariff. There is also the bonus of increased resiliency for your DHW and then there are the running cost savings.

The cost of a T25 is £50,000, with savings per hour (including maintenance) of £1.50, so it requires 33,333 run hours to achieve payback. Saving just £3,750 per year means the only driver is carbon savings and that would not alone warrant the investment in an existing building.

If the building is right for CHP, then it is worth considering as an upgrade. CHP saves money when it runs, it’s the opposite of a boiler which costs money when it runs so we want that to be off and the CHP on.  The ideal applications are ones with large DHW loads where people are residing. With a large care home, the expectation would be to run a CHP 24 hours per day during the heating season, dropping to 12-14 hours per day outside heating season. This gives us an average running of 18 hours per day throughout the year or 6,700 run hours per year. That equates to a five-year payback, and with 10-year  operating plan in place the potential savings will be £50,000 if your building is suited to the technology.

Alexandra House, operated by Care South, is a two-storey, 58-room residential care and nursing home in Poole, it has a T20 CHP working in conjunction with a custom-built 2500-litre buffer vessel, as well as a cascade of two AO Smith Upsilon 110 boilers and two AO Smith IT500 indirect calorifiers. This is all supplied as a complete package, alongside ancillaries and backup heating components via electric immersion elements. The design of the hot water and heating system at Alexandra House is projected to achieve more than 7,100 CHP run hours per year, resulting in annual carbon reductions in excess of 44.5 tonnes and providing expected energy savings, inclusive of CHP maintenance costs, of £7,500.

In the third, and final part, we will take a look at the environmental impact of m-CHP and explain how it can deliver energy and heat whilst reducing a care home’s emissions…

Bromsgrove Leisure Centre plant room.

Sustainable Energy For The Leisure Industry – Part 1

From hotel accommodation to restaurant kitchens, spas and swimming pools, leisure estates generate a wide range of electrical and heating demands. In terms of usage patterns, demands can be significant, often varied, but also constant, creating a complex range of challenging applications.

Currently, around 40% of UK greenhouse gas emissions are accounted for by heating, cooling, ventilation, the provision of hot water and lighting properties. The impetus then is to reduce operational energy use, prioritising reduction in energy demand and consumption over all other measures. This means in-use energy consumption will need to be calculated and publicly disclosed on an annual basis, as laid out in the new, mandatory Streamline Energy & Carbon Reporting (SECR) regime. This is designed to raise awareness of energy efficiency, reduce bills, and save carbon by driving an increase in renewable energy supply and prioritising on-site renewable energy sources.

From new builds to refurbishment projects, the leisure estate is faced with a myriad of choices, and, if medium or large organisations they are going to be increasingly held accountable by SECR for decisions that must ultimately balance both CAPEX and OPEX with this new sustainability.

A difficult task for an industry where heating and hot water are considered business-critical services and demands in terms of higher temperatures and usage far outstrip anything seen domestically.

The key then is to understand how hot water, heating and power demands can be cost-effectively brought into balance by maximising contribution to a building’s overall efficiency. Identifying technology concepts that help address such sustainability is only half the battle though, there still remains that need to reduce total cost of ownership. Space savings, ongoing supply reliability to simplified control and maintenance are all means to reduce costs and provide peace of mind when investing in a business-critical hot water and heating system.

Innovo commercial water heater by AO Smith

A.O.Smith’s Innovo Water Heater

Adveco's MD commercial condensing boiler

Adveco’s MD. A range of high-efficiency Floor-standing condensing boilers

Whilst arguments continue to rage regarding the validity of gas for a low carbon future, the reality is that for the foreseeable future our national infrastructure will continue to remain heavily reliant on the provision and improved use of gas. For leisure projects that face the most stringent legislation and oversight, high-efficiency condensing boilers, such as Adveco’s MD range, and room-sealed condensing water heaters, such as A.O. Smith’s BFC and Innovo units, remain a realistic and effective means of meeting the demands for improved sustainability.

When it comes to the refurbishing of existing building stock, which is where the greatest advances can be potentially made, installing solar thermal is going to be better from a renewables’ perspective. But we also recognise that this approach can be constrained by limitations of space, delivery timeframes and budget. ROI can also be much slower to achieve, despite the welcome new Smart Export Guarantee (SEG) legislation, under the which SMEs installing new solar photovoltaic panels, will from 2020, be able to profit from exporting excess generated electricity to the grid.

A smart approach would be to combine two heat generators, such as gas and solar, or gas and air source heat pump, although this can generate new issues of logistics, space requirements and increased complexity of plant, leading to a higher CAPEX cost compared to a pure condensing heating system. The advantages for a commercial leisure site from a hybrid heat pump/gas boiler system is the ability to smartly balance the heat generators, guaranteeing all-important high system temperatures while reducing the maximum power consumption for greater efficiencies and lower operational costs.

Adveco 2020 Product Overview Now Available

The 2020 Adveco Product Range brochure serves as a quick reference document covering a wide range of products and services provided by Adveco and A.O. Smith. The current range incorporates commercial hot water and heating equipment including: condensing gas water heaters; storage tanks, oil & electric water heaters; solar thermal; boiler cascade systems; stainless steel cylinders, thermal storage tanks, carbon steel buffers, combined heat & power (CHP); Air Source Heat Pumps (ASHP). These technologies are the building blocks for Adveco’s bespoke packaged plant rooms and system offerings. All supported by our applications and field engineers who provide expert commission services, warranty maintenance and training.

If you are seeking support in the design, supply, commissioning or servicing of business-critical hot water, heating and power then this brochure is a useful tool to have to hand.

You can download the brochure now.

Hybrid Approach

Adveco’s Technical Director Bill Sinclair discusses the energy challenges facing facility managers when it comes to achieving sustainability across the built estate in the latest issue of Tomorrow’s FM Magazine.

Read the full article here

What can you do to protect your business from power outages?

While it was a common experience throughout the 70s, this month’s National Grid failure and subsequent blackout caught many businesses by surprise. The simple fact is that we have become complacent, expecting a consistent energy supply, and the resultant disruption that was seen across the country reflected this.

The National Grid failure was a rarity, but it is important to realise that such an occurrence had been predicted by experts who have questioned the risk associated with the ‘energy trilemma’. So called, because of three key challenges that face the sector, the risks associated with the need to decarbonise power generation in the cheapest possible way while guaranteeing security of supply.

Last November, energy secretary Greg Clark triumphantly declared the ‘energy trilemma’ to be over in a speech to Parliament stating that: “by the mid-2020s green power will be the cheapest power.” As is clear, his statement glossed over the third and by far most important aspect, security of supply.  In response to the recent blackout, Lord Adonis, former chair of the government’s National Infrastructure Commission, said: “This is a big wake-up call for National Grid. Their resilience is below par.”

National Grid’s director of operations Duncan Burt acknowledged the “immense disruption” the blackout had caused, citing the near-simultaneous loss of two generators being more than the grid was routinely prepared for. Subsequent investigation now points to a lightning strike on the network near Cambridge, a common occurrence, and critically the almost instantaneous total loss of supply from the Hornsea wind farm, which is currently under construction off the coast of Yorkshire. It cut from 800MW of production to 0MW in under a second.

The increasing reliance on extremely high volatility renewable energy sources (RES) electricity, where there will inevitably be peaks in supply of electricity, remains a concern for many considering the future consistency, and therefore cost, of supply from the grid.

Colin Gibson, former director of National Grid, and grid engineer, Dr. Capell Aris,  suggest ministers should impose limits on the construction of new wind and solar farms to help avoid a nationwide blackout, while some existing turbines and solar panels may have to be disconnected, and new developments restricted, to “secure” the system in the aftermath of this month’s major power cuts.

So what options are available right now for businesses seeking to maintain 24/7 operations? Whilst Lord Adonis placed focus on the resilience of transport and health systems, the bottom line for any business is the critical nature of consistent power for operations.

Solar photovoltaics (solar PVs) have retained popularity amongst organisations looking to lower emissions and increase their environmental responsibility as well as saving significant costs on energy. It also offers extra security when it comes to your power supply. However, there will always be limitations in terms of installation space for panels and the process of designing and installing can be lengthy. CAPEX can also be relatively high meaning ROI is slower, even with the government’s new SEG legislation setting new tariffs for exporting excess energy to the grid. To protect business operations from service loss, PV is more of a long term response.

A more rapid and viable sustainable option for commercial operations of any size are micro-cogeneration or m-CHP systems, which use the existing gas supply to run a specially configured engine that generates electrical power onsite. In addition, the m-CHP will recover the normally wasted heat generated by this process, this can then be used to heat water for other applications including essentially ‘free’ space heating.

Adveco’s Totem M-CHP is capable of delivering electrical outputs from 10 to 50 kW with a total unit efficiency of up to 107.4%. This makes the TOTEM series of cogenerators among the most efficient combined heat and power units available today.

For businesses wanting to reduce running costs, reduce emissions from site and guarantee a cost-effective level of service supply M-CHP ticks all the boxes. New installations of m-CHP are also included in the SEG legislation, like PV systems this enables them to sell excess produced power back to the grid.

More importantly, TOTEM’s compact design requires less space (it is just under 2m in length and 80cms wide) and can be assembled onsite in a matter of days. Relative to other onsite technologies m-CHP provides a relatively rapid, deployable response to any concerns over the consistent provision of affordable energy.

m-CHPs from Adveco are in operation throughout the UK, from first responder sites to offices, hotels, universities and schools. Discover more about the advantages of m-CHP in this helpful booklet.

Micro-CHP Becomes The Smarter Choice For Lower Cost Energy

Under new laws introduced by the government, the Smart Export Guarantee (SEG) guarantees small businesses installing new micro combined heat and power (m-CHP) up to 50kW, such as the Adveco TOTEM, and solar photovoltaic (PV) panels will receive a payment for exporting electricity to the grid from the start of 2020.

Energy suppliers with more than 150,000 customers will be obliged to offer a minimum of one export tariff each to small-scale electricity generators for each unit of electricity they sell to the grid, based on readings taken from a suitable smart meter. Meters must be capable of providing export readings every half an hour, even if the tariff is not paid on a half-hourly basis. Those who supply half-hourly readings are expected to be offered a wider range of tariffs.

The legislation appears flexible and will enable energy suppliers to pay businesses for exporting electricity to the grid at times of peak demand, whether it was renewably generated or not. Looking to early export guarantee type tariffs currently available, the expectation is that suppliers will offer a payment of around 5.5p per kilowatt hour.

To qualify for the Smart Export Guarantee, small scale generators will need to have renewable energy systems installed to meet the standards of the Microgeneration Certification Scheme (MCS). Payment of the SEG will not be linked to or affected by any other grants or loans, with the exception of those benefitting from the earlier Feed-in Tariff scheme which closed at the end of March 2019. SEG will not apply to those businesses, but they can apply to swap from the feed-in tariff to SEG if they wish.

For businesses choosing Adveco’s TOTEM m-CHP, the greatest advantage has been the up to 29% reduction in energy costs. With the new SEG tariffs in place, m-Combined Heat and Power becomes an even more attractive option for those seeking to produce electricity onsite. The electricity output from the TOTEM m-CHP’s gas-powered engine not only provides electricity that can now be fed back to the grid at a profit, but also for each kWh of electricity generated approximately 2.5 kWh of free, high-grade heat is also recovered which can then be used for central heating or water heating in the building.

To learn more about the advantages of m-CHP speak to Adveco today or download the brochure.

Harnessing the power of off-site construction

Adveco’s Packaged Plant Room brochure explains the advantages of relocating essential heating and hot water services to increase the availability of valuable internal areas, accelerate project timescales, improve quality of installation and substantially reduce on-site labour.

With a wide product offering and experience in full system design, Adveco provides a single source of supply for the delivery of complete heating and hot water systems precisely tailored, built and delivered to fit the specific needs of your project.

You can download a digital copy of the new brochure here.

Reducing Energy Costs Through Cogeneration

Cogeneration utilises onsite production by a gas-powered engine to allow a building to generate electricity and recover energy from the process which can then be used for water heating or central heating. Download the 2019 brochure now and discover the advantages of Adveco’s TOTEM m-CHP and see how it can transform your next project…