Green light for solar hot water

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Dubai’s new ‘green’ building regulations are expected to mandate that solar water heating systems must also be installed to provide 75% of domestic hot water requirements. This will herald major opportunities for the MEP sector. We speak to a local leader in the field, Ecoval Trading LLC MD Jim Sebastian.

The potential of the solar water heating market in the UAE is indicated by the fact that Ecoval is now the number one global distributor for Solahart of Australia. “Italy is number two and South Africa number three.” Sebastian is convinced that Dubai’s green building code will play a major role in the exponential growth of this sector. “It will definitely have a big impact, and is already stimulating the demand for renewables.”

However, a major hurdle for the renewable sector at present is unsustainably low energy prices.

“Energy prices are so cheap there is no real incentive for people to save electricity and water, let alone spend extra money on renewable systems.” Having said that, while the sector only comprised as few as six companies two years ago, “now we count up to 30,” says Sebastian.

“The surprising thing is that most of these companies are new entrants. The major established building services players locally have not really entered the UAE solar sector, probably because they are in a comfort zone. Some local players have made inroads, but they are not in the big leagues.” Sebastian predicts the market will reach a saturation level, at which point consolidation will take place. Thus it is important for the market fundamentals to be in place right from the outset, says Sebastian.

The company was established in Dubai in 2002. “We started off with heat pumps for swimming pools, with the solar water heater business slow to catch on until 2007 with Sheikh Mahommed’s green building decree. That helped us a lot.” In terms of heat pumps, Ecoval was among the top two in the industry, with a locally-manufactured unit. “We foresaw that at some point competition would definitely come in, especially from China.”

Chinese competition

However, Sebastian says the company did not anticipate the extent of the competition, which resulted in the virtual demise of the local manufacturing base for heat pumps. “There used to be up to four local manufacturers, but now it is just so much cheaper to import from China, and the quality is comparable.” It is for this reason Sebastian is urging the solar water heating sector to consolidate itself in the face of the relentless competitive pressure from such juggernauts as China. “So we left that industry and got into other avenues of business like ICI steam and hot water boilers, Alfal Laval heat exchangers and Sanyo PV systems.”

The secret to any company’s success, says Sebastian, is differentiating itself from the herd. “You have to make yourself stand out from the competition, and let the market not only know what you do, but how you do it differently.” This also means one has to be open to new ideas and trends. “When I was with my previous company, I was introduced to the Solahart product, with a consultant friend telling me the future lies in solar energy.” Sebastian says his initial research made him aware of “a lot of negativity about solar and misunderstanding of the market potential.”

At that stage Solahart did have representation in the Middle East, but it was looking for a way to break out even further. “It is easy to sell electric water heaters, as there is a common need for it. But for solar water heaters you have to create a want. It requires an entirely different perspective.” As a result, Sebastian invested heavily in the sector … and admits with a smile: “It could have gone either way.” However, his confidence in the Solahart brand was soon to reap rich dividends. “One thing I have learnt over the years is that if you do not have a good brand and a high-quality product, it is never a long-term venture. I have always held close to my heart the idea that quality is remembered long after price is forgotten, and that happens all the time.”

Sebastian had his work cut out for him, as that stage there was little awareness locally about solar water heating. “They knew about it, but did not believe in it. Even now, the most common questions is why do we need hot water in this region?” And yet hot water is a major consumer of electricity after air-conditioning, says Sebastian. Electric water heaters are prevalent in the winter months, when the temperature can drop as low as 15˚C – “and yet everyone wants piping hot water at 60˚C. Therefore I do not comprehend the reasoning that maintains we do not need water heating.”

Sebastian says the boom in construction, especially high-rise and villa developments, has placed an extra burden on electricity generation, as all these have electric water heaters. “We are urging customers to install solar water heating systems, and thereby save up to 75% of the connected electric load.” Another problem is that while consultants may be aware of the technology and its potential benefits, “when it goes out to tender, it often gets sidetracked in value engineering.”

However, the latest trend towards building efficiency has placed the spotlight firmly on solar water heating as a cost-effective option to realise immediate savings.

In addition, Solahart products are particularly suited to the region’s harsh climatic conditions, when some similar European products are known to have overheating issues. “Solahart has a presence in 90 countries, and has been manufacturing solar water heaters exclusively since 1953. Its technology is characterised by the drainback principle, whereas most other manufacturers utilise fully-flooded systems. “What happens normally is that most people place everything on the roof, which means the circulating fluid is always in the loop, the temperature goes too high, and then the pumps and pipes fail. Our system is very simple, as it switches and drains back off before it can overheat,” explains Sebastian.

In addition, the collectors comprising the system are extra strong and durable. Solahart has six different collectors, depending on the specific requirement. “We install and commission the systems on a one-stop shop basis from design to installation. We even assist in calculating the total hot water requirements, the number of collectors and what back-up is needed, as consultants are normally so busy.”

The average lifespan of a Solahart system is anywhere from 12 to 25 years, depending on routine mechanical equipment maintenance. “We have a maintenance contract with Holiday Inn, for example, whereby we supply technicians and ensure that the systems are running properly.” Sebastian says that one particular Solahart system reloca- ted to the company’s head office in Australia had been in operation for an astonishing 50 years.

Solar thermal versus solar PV

Solar power encompasses both solar thermal and solar PV. Firstly, efficiency is much higher for solar thermal. Up to 80% of the sun’s energy can be exploited with a thermal solar collector, whereas with a PV collector, sunlight-to-electricity conversion rates average about 12% to 16% only.

The rule of thumb is that the energy available from the sun is about 1 kW a square metre. This is equivalent to 3 412 BTU/h/square metre. Therefore if you can get 80% efficiency using a solar thermal collector, you would only need about 37 square metres to generate 100 000 BTU/h, or the amount of heat generated by a typical gas furnace.

Thus a solar thermal system would require much less space (and many fewer collectors) than a solar PV system. Not only that, but solar thermal collectors are about five times cheaper than solar PV panels. So you have a scenario in which you have a system that is six times more efficient at 20% of the total cost of its rival. How then can solar thermal not be dominating the solar industry?

Of course, it is not quite that simple. For one, heat is difficult to store without a thermal mass.

Passive solar homes will likely incorporate thermal mass walls (that is, concrete or other masonry) to store collected heat. Yet this can only be achieved via a passive solar design, starting at the home’s conception. It is difficult to add thermal walls and other passive solar collectors to an existing home. Therefore, when retrofitting a solar thermal system, you will have to use an active system, which uses a transfer fluid and a large water storage tank.

Furthermore, you will need to calculate the intensity of the sun at different times of the year. In addition, because of clouding, you may need to have a back-up system also. All these complications and distributed yet fast-accumulating costs may be why solar thermal space heating is still more possibility than actuality.

Another big advantage for solar PV is that it is usable year round. A solar thermal space heating system will sit idly by during the long summer months while a solar PV system will provide usable electricity all year. The system would be at its most efficient just when you need it most.

However, solar thermal is said to represent the future of solar energy and a ‘green’ electrical grid. There have been new innovations in thermal storage techniques, if only practical on a commercial scale at the moment. For the residential homeowner, a solar thermal hot water system can result in quick, tangible savings, especially as hot water is the second most consumptive energy user in a home.