By Gerhard Hope
Why are we wasting so much electricity on water heating when solar is the way to go?
The newest superlative for the MENA region is Abu Dhabi's announcement it is building the world's largest concentrated solar power (CSP) plant. The figures are suitably impressive: a total investment cost of AED 2.2 billion, and a 2.5 km2 solar field of 768 parabolic trough collectors in the desert at Madinat Zayed.
Yet at the end of the day, one has to bear in mind that Abu Dhabi has set a relatively modest target of generating 7% of its total electricity needs via renewables by 2020. Not to mention that the cost of producing electricity from Shams 1 will be three to five times the average cost of producing electricity from natural gas.
It seems that Shams 1, which will take two years to construct, is one of those ‘iconic' projects so beloved by the region. These ‘statement' projects are the last word on a particular topic, the construction industry's equivalent of a ‘shock-and-awe' tactic.
Shams 1 is ten times the size of the PV array at Masdar, lauded at its launch as the largest in the MENA region. However, the significance of the project was overshadowed when tests revealed that the dusty climate reduced the efficiency of the panels considerably. Clearly one of the aims of Shams 1 is to restore some of Masdar's tarnished glory as the region's leader in renewable energy.
While Shams 1 is impressive and cutting-edge, it is nevertheless a long-term project, as is the region's nuclear ambitions. Of more immediate concern - and, indeed, excitement - is what is happening in the solar energy sector in the UAE as a whole, which offers tremendous opportunities to the MEP industry, in turn.
It is estimated that there are anything from 30 to 50 companies offering various ‘solutions' at present. Most of these companies are new entrants, having appeared on the scene within a few brief years. (One is reminded of the old Wild West frontier of the US, where gold-rush towns found themselves besieged by prospectors. Except now the new gold seems to be sunshine.)
Unfortunately, the bright potential of the solar energy market has been somewhat dimmed by cheaply-imported, inferior-quality products that seem to break down as often as the sun shines. This has made it difficult for reputable suppliers to make inroads with more expensive, but far better quality, systems. Another serious problem is a lack of integration expertise and installation certification - these are both areas where the MEP industry can make a significant contribution.
Of particular interest to the solar thermal sector is the news that Dubai's new ‘green' building regulations will stipulate that solar water heating systems must be installed to provide 75% of domestic hot water requirements. Not many people realise that water heating is one of the major consumers of electricity in the region. If you look at large users like hotels and industry, the costs are even more significant.
A solar thermal collector can exploit up to 70% of the sun's energy, whereas the average sunlight-to-electricity conversion rate of a PV collector is only about 12%. Not only are the space requirements far less, but solar thermal collectors are also about five times cheaper than PV panels. Thus this niche renewables sector has a bright future, and also stands to make a contribution to energy savings and resource efficiency.
To those who question why we need hot water in the desert - well, there is a lack of awareness about solar water heating in general. Everyone expects piping hot water, even in winter, and gives little thought to the energy wastage of electric heaters. (One major MEP consultant said he believed hot water should be designed out of public restrooms, as it is a an utter waste).
So while major projects like Shams 1 get all the attention, more immediate energy savings will be through individual actions and choices. Which is food for thought the next time you have a hot shower.
Gerhard Hope is the editor of MEP Middle East.
I agree with Gerhard about the far superior ROI in utilising Solar waterheating as against PV. The cost of generating 1KW (1000w) of power may require some thing in the range of AED. 20/35,000 at the least while a system with adequate storage for optimum production can add a 15 or 20 more. In our scheme of things 1KW is next to nothing. It certainly is not enough to run a one ton window AC machine a day in summer(even half a day). If you are considering this option... it's got to be for a green award of a sort. In contrast Solar water heating is far more superior in terms of ROI (Return on Investment). This is owing to the high cost of water heating we are used to. To take an example an average hotel stores at any given time upto 25,000 gallons of hot water (Water constantly heated upto atleast 60'C to prevent Legionella bacteria thriving). These water storages while being constantly boosted with electrical thermal heating can be easily complemented with solar power. An array of Solar thermal collectors plumbed in to these storage tanks can greatly reduce the workload of this electrical resistance elements emmersed in them. The advantages are so obvious. 1. Not need to eliminate the existinng system. 2. Upto 100% reduction on power bills depending on the size of the solar array. 3. The paybacks can begin within two years of installation at the least. 4. Can be retrofitted at any hotel or plant which Operates a Calorifier or boiler. 5. Expensive storage tanks for the solar system not required. 6. Whereever solar arrays are not practical (They require decent roof space) indirect solar heating with Ambient air heatpumps may be fitted. Abmient air heat pumps operate at a COP (Co-efficient of performance) of around 3 to 4 as against the submerged heaters always under 1. That is a potential saving of upto 75% on your power bills. These technologies are practical and easily make business sense allthough less glamouress. Contact me if needed - firstname.lastname@example.org Call me for more details on the matter