Why solar thermal energy still shines

Is the sun a renewable resource?  Well, technically it isn’t, as it will burn out in about five billion years.  But for all practical purposes, 5 billion years is the same as a renewal source.  In contrast, world oil production started in 1859 and will start declining sometime in the next five years.  So, what’s the most reliable natural resource to provide our hot water from for our homes? The sun, oil wells, or electricity?

Remember that electricity in New Brunswick is roughly 60 per cent from fossil fuels.

If you chose the sun, you may be on to something sustainable.  People thinking about solar energy systems may confuse solar thermal with solar photovoltaic (that provides the electricity for your calculator).  One of the types of solar thermal uses a liquid, propylene glycol, to avoid freezing concerns while effectively transferring heat from the sun to your hot water.

A typical collector consist of a number of black-painted aluminum fins or plates bonded to copper tubing in a box that’s covered by a tempered glass cover. The glycol is pumped through the collector on a roof or wall, absorbs heat and transfers it, through an exchanger, to a storage tank for use when required. The interesting part is that there’s no charge for the energy provided by the sun, so it’s inflation-proof.

At the surburban home of Gordie Smallwood of Moncton, you can find a solar thermal system he’s built with reclaimed collectors. The collector area on his roof is 160 square feet (roughly 8 x 20 feet). That’s bigger than your typical system. His hot water is totally solar heated, with the excess going to partially heat the house.

As Gordie explains, “this is not rocket science. The technology has been around for a long time and there are lots of good manufacturers out there.” The day I saw his unit, the collector output was at 140 degrees Fahrenheit.

I also spoke with Gordon MacDonald of Harvest Energy Solutions about solar thermal. He suggested that people take all of the energy conservation steps that they can as a first step to energy independence, being the biggest bang for your dollar. Each site has challenges as the building may not have a good southern orientation, the angle of the roof may be less than optimum and shading may exist. The roof structure should be in good physical shape to support the weight of the collectors, and space is required for the storage tank, among other considerations.

The cost of a system will vary depending on your requirements – how much heat can you effectively use? For example, the heating demand of a home varies greatly in a winter and is not required at all in the summer. However, hot water heating requirements are relatively stable throughout the year and therefore more economic to design for.

Apparently, commercial and industrial users of large quantities of water are the big winners with solar thermal, as the economies of scale kick in and many companies use hot water only during the day, minimizing storage requirements. Paybacks are quick.

So, if there is an economic advantage, why aren’t more residences and businesses using solar thermal? Very simply, initial installation costs are in the thousands of dollars, and you can rent an electric water heater from N.B Power for less than $10 a month. Which would most people logically choose? Lower first cost wins almost every time. In addition, there are few installed systems in New Brunswick to serve as comfort for those of us who only believe in what we see. Lastly, with a small number of retailers and trained installers, you may understand why solar hasn’t heated up our interest.

The federal government has several programs that reduce payback time and stimulate the industry. The EcoEnergy Retrofit program provides $1,250. The temporary Home Reno Tax Credit has a maximum benefit of $1,350. And there may be others. Be careful to ensure that you qualify and that you follow all the right steps.

In Kingston, Ont., the utility will provide a two-panel unit for $49 a month. Larger sizes are slightly higher. You can also purchase the system for $5,000, not including installation. Other utilities in Canada are getting involved as well, including Manitoba Hydro, Enmax and FortisBC.

What could New Brunswick do to encourage solar water heating? NB Power provides hot water tanks that use electricity at a monthly rental rate. That electricity mostly comes from non-renewable sources (oil, coal, and natural gas). The province could require NB Power to lease solar thermal hot water systems, as well. At 10,000 new systems per year, that’s 20,000 collectors or more. These could be produced locally if we chose to do so.

If you include all of the installation work, you have the start of a new green industry in New Brunswick.

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One comment

  1. kz1000guy · December 7, 2009

    I just discovered your site. I found this to be good commentary and will be reading the rest soon. I have a vested interest in NB Power, but have been watching solar on and off over the years. I have recently looked back at the subject after purchasing a new house. There are now a couple of ideas out there that are about as basic as buying a good appliance and plugging it in. Solar Evacuated tubes systems for water heating are almost a no-brainer now. And could reduce residential bills by half in most cases. Providing hot water and some space heating. Your suggestion would be a step, actually several steps, in the right direction with the proper government energy policy. A solar system could be installed to offset a residential power bill, and like you suggest financed or leased through NB Power, or something similiar, until it’s paid off. Then the customers bill drops by the appropriate amount. The price, especially for a new construction, would be basically unseen by the customer, but the results the same, with the added bonus off a big drop in the monthly bill in a few years when it’s paid off.

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