With the cost of conventional energy ever increasing, consumers are becoming more interested in the use of solar energy. But which solar energy technology makes the most sense for the average consumer, solar heating or solar electric?

A solar heating system generally consists of solar collectors, a water storage tank, a pump and automatic controls. The estimated cost of a hot water solar heating system for a typical single family home is between $4,000 and $8,000, including installation. The system will replace approximately 80% of the energy used by a conventional hot water system, and represents a cost savings of $500 to $600 a year. The payback will average between 5 to 7 years after tax credits, meaning that after 5 to 7 years the total cost savings will have paid for the initial cash investment.

The components of a solar electric system are the photovoltaic solar collectors, an inverter, a charge controller and batteries. The projected cost of a grid-tied solar electric system for the same typical single family home is from $25,000 to $35,000 and will supply approximately 20-25% of the electricity usage of the home. The yearly savings would be between $500 and $600. The payback of the system is estimated at 15 to 25 years.

The initial costs of both of the solar hot water heating system and the solar electric system may be reduced by federal tax credits and state tax incentives. The cost savings per year and payback time for both systems will vary depending on the exact costs of the system components, actual current energy costs and future increases in energy costs.

Neither system is 100% efficient, since energy is lost due to conversion processes. Solar hot water heating systems are considered to be between 35% and 50% efficient, compared to solar electric systems which are 4% to 13% efficient.

In our opinion, because of the lesser initial expenditure, the quicker return of the investment and the higher rate of efficiency, the solar hot water heating system is the better, more cost effective choice.

The European Member States have to work out a Renewables Action Plan this year, outlining how it will reach its 2020 target
by Werner Weiss and Peter Biermayr
London, UK [RenewableEnergyWorld.com]

The European Union and its Member States have committed themselves to achieving a 20% share of renewable energy in Europe’s final energy consumption by 2020. As only three renewable sources (biomass, geothermal and solar) generate heat, it is crucial to clarify how these different sectors can contribute to the renewable energy target. A new study being released this autumn – Study of the Potential of Solar Thermal in Europe, which has come from two Austrian bodies (AEE – Institute for Sustainable Technologies and Vienna University of Technology) examines the growth that can come from solar.

Obviously, solar thermal systems will be needed to provide a substantial share of the low temperature heat: deep geothermal sources are limited to a few locations in Europe, and shallow geothermal is considered within this study as an energy efficiency technology; biomass will be used for transport fuels, electricity generation and medium-to-high temperature applications.

In order to provide the European Union and its Member States with substantiated information on the solar thermal contribution to the 20% renewable energy target and its long-term potential, detailed surveys were conducted using a representative sample of five European countries – Austria, Denmark Germany, Poland and Spain. The information gathered was then extrapolated to cover the 27 EU countries. The study examined both the technical and economic potential of solar thermal technologies, for different applications, including low-temperature industrial heat requirements and cooling.

In order to determine the potential contribution solar thermal could make to the overall heat demand in the selected reference countries, a model was developed for the future demand – taking into account energy efficiency measures. Using this model as a base, future heating and cooling demand was calculated for 2020, for 2030 and 2050. The model includes three scenarios and focuses on the following segments:
* space heating of residential buildings
* hot water preparation in the residential sector
* space heating in the service sector
* industrial low temperature heat (up to 250°C)
* air conditioning and cooling in the residential and service sectors

The three scenarios are a ‘Business As Usual scenario’ (BAU); an ‘Advanced Market Deployment scenario’ (AMD), which includes financial and political support mechanisms such as subsidies and obligations, moderate energy efficiency measures and improved research activities; and a ‘Full R&D and Policy scenario’ (RDP), which includes substantial financial and political support mechanisms, energy efficiency measures and research activities.

Contribution of Solar Thermal to the EU 20% Renewable Energy target

Assuming there is a 9% reduction of the overall final energy demand due to energy efficiency measures by 2020 (compared with 2006), then solar thermal would make up 6.3% of the European Union’s 20% renewable energy target under the RDP scenario, and 2.4% under the less ambitious AMD scenario. The share of renewables in 2005 (to the EU-27’s total energy consumption of 13,609 TWh) was 8.5%. To reach 20%, an increase of 11.5 percentage points in renewable energies is required across the EU-27 countries by 2020. The contribution of solar thermal to that increase would be 12% according to the RDP scenario, 4.5% according to the AMD scenario and 2.9% in the BAU scenario.

To reach the goals of the RDP scenario, a 26% average annual growth rate of the European solar thermal market is needed up to 2020. (By comparison, the average annual market growth in Europe between 2000 and 2007 was 12.4%.) A 15% average annual growth rate is required to reach the goals of the AMD scenario and a 7% growth rate for the BAU scenario. The resulting total collector area by 2020 would be between 97 million m2 (BAU) and 388 million m2 (RDP). These collector areas correspond to total installed capacities of 67.9 GWth and 271.6 GWth, respectively.

Economic Effects

According to the RDP scenario the effect on employment would be considerable. In total, the solar thermal sector would encompass 470,000 full-time jobs in 2020, in the European Union domestic market alone. €214 billion would be required in the solar thermal sector to reach the 2020 goals of the RDP scenario. This includes production, engineering, trade and installation of solar thermal systems from 2006 to 2020.

Solar thermal contribution to the energy supply and CO2 reduction

The solar yield in the RDP scenario is 155 TWh in 2020. This corresponds to an oil equivalent of 22 billion metric tons. Taking this oil equivalent into account the annual contribution to the CO2 reduction by solar thermal systems is 69 million metric tons.

Technology Innovation

Stepping up solar on this scale will require innovation. In order to use the potential much larger roof and facade areas will be needed for the installation of solar collectors.

Large-scale solar renovation of buildings will make use of prefabricated elements, with solar providing space heating, cooling and hot water. Combisystems will play an essential part, and a key issue is the development of thermal energy storage.

Long-Term Potential – Beyond Domestic Hot Water

In 2050, the solar thermal contribution to the European Union’s (EU-27) low temperature heat demand ranges from 47% (RDP scenario) to 8% (BAU scenario).
The corresponding annual solar yields are 1552 TWh (RDP) and 391 TWh (BAU). The collector area needed to reach these goals is between 8 m2 (RDP) and 2 m2 (BAU) per inhabitant in the EU-27. The resulting total collector area is between 3.88 billion m2 (RDP) and 970 million m2 (BAU).

If solar thermal is to contribute significantly to the long-term heating and cooling demand in EU-27 countries then the primary focus in central and northern Europe must be on systems for space heating (solar combisystems) and in the Mediterranean area on systems providing space heating, hot water and air conditioning (solar combi+ systems).

If the focus remains solely on solar thermal systems for domestic hot water preparation, then the solar thermal contribution to the long-term final energy demand will be limited. By 2030 the full potential for these applications will have been reached and the market would be reduced mainly to the replacement of old systems. Another important segment with considerable potential is low-temperature process heat for industry, (up to 250°C).

With upscaled R&D and market/political support, solar heat can make a valuable contribution to Europe’s energy future. It’s the right moment – in fact, without the renewable heat sector, the 2020 targets will not be reached.

Werner Weiss is at AEE – Institute for Sustainable Technologies, Gleisdorf, Austria. Peter Biermayr is with Vienna University of Technology Energy Economics Group, Austria.

The full version of the Solar Thermal Potential in Europe study is available: http://www.estif.org/.

This study was prepared in the framework of the EU-funded project RESTMAC, TREN/05/FP6EN/S07.58365/020185. The Solar Thermal partner in the RESTMAC project is ESTIF, European Solar Thermal Industry Federation.

Solar heating system gets prominent display during the 2009 solar tour.

http://wake.mync.com/site/Wake/news/story/42654/solar-powered-homes-businesses-go-on-display/

In a previous blog we posted a video that showed how to “get the air out” of your glycol solar heating system when you it. An astute customer realized that since he was planning to mix his glycol with his water he could reduce the number of times he needed to cycle the charging pump by starting with straight water. After he has charged the system with straight water (which doesn’t foam nearly as much as a water/glycol mixture) he can then finish the charge by switching to a bucket of straight glycol. He needs to pay attention to his ratios as well as checking his concentration after he is finished but this process greatly reduces the times he needs to cycle his system to get the air out. By eliminating the issue of foaming in the bucket the charging time is greatly reduced.

Thanks Jason.

When trying to diagnose a system it is frequently important to determine whether the pumps are working in your solar heating system. The first (and least accurate) method most contractors go with is feeling the pump to see whether they are vibrating. This can be misleading because vibration from nearby mechanical equipment can cause you to assume the pump is spinning when it might not be. A very easy and accurate way to determine whether the pump is spinning is to remove the bleed screw from the top of the pump (see video). When you remove the bleed screw (not available on Taco pumps) you will see an inner slot on the end of the shaft. You can only see this when the pump is not spinning. Since the slot is directly connected to the shaft and impeller, if the slot is rotating you know the pump motor is spinning. Turn the power off and you should see the slot.

By removing the bleed screw and accessing the head of the pump you can also spin the shaft freely with a slotted screwdriver. You should be able to feel if the shaft is binding in any way.

This is the time of the year when the calls start rolling in. “I have a single tank solar water heating system and the water heater has stopped working.” This is not a service call you should need to run out on.

Using a standard electric water heater for both your solar storage as well as providing your back-up heating has many advantages including; reduced floor space, ability to use standard tanks, less standby losses from the tank, better heat recovery, and less cost. But now we come to the rub. Electric water heaters have a thermostatic breaker built into the top element. When the thermostat senses temperatures over 170° F it automatically trips this safety breaker. This breaker is designed as extra protection in case you have a run-away element in your tank to keep the system from getting too hot.

Frequently a solar water heating system will supply 100% of your hot water needs during May through September. If at any time during that period the top of your tank exceeded 170° F the tanks thermostatic breaker will trip. As the cooler and cloudier weather sets in the back up element is no longer able to kick in and you receive a service call. Fortunately, the fix for this problem is simple and within the reach of even the least proficient home-owner.

Simply remove the cover plate over the upper element, depress the red button with the eraser of a pencil and voila you are back and running again. (see picture)

Water Heater Reset Button

So next time you get this call don’t fret and think about the little red dot.

After reviewing dozens of websites, we have come up with a top ten list of our favorite solar water heating installer websites.

Each of these websites has introduced their company to the potential customer with content that is informative, clear, concise and up to date. Each one has provided a description of a typical solar water heating installation, some with illustrations. All of these websites have also included their company’s solar energy credentials and the reasons why they should be chosen as the customer’s installer. Some have incorporated photographs of their recent installations, with customer feedback. In addition each one has presented the information in a professional looking website that is easy for the user to navigate.

Since websites should be designed as marketing tools, each of these websites has been graded on the elements of aesthetics, content and navigation, and have been given a numerical score in each. Additionally each website has an SEO grade based on its grading from the website http://www.websitegrader.com. Having a great looking website is only part of the battle since you need the customers to be able to find your website as well. If you notice our top website isn’t the best looking and also doesn’t have the best content but it does have the highest visibility to the search engines and is passable in the other respects.

Our top ten list of solar water heating installer websites is as follows:

#1 ECS Solar Energy Systems, Inc located in Gainesville, Florida
http://www.ecs-solar.com/
Excellent slide show of various types of solar panels installed on homes.
Aesthetics 5, Content 8, Navigation 10, SEO Grade: 91

#2 Dovetail Solar And Wind located in Cincinnati, Ohio
http://www.dovetailsolar.com/index.htm
Extensive “frequently asked questions” area with important information.
Aesthetics 7, Content 10, Navigation 10, SEO Grade: 68

#3 Solar Assist, located in Eugene, Oregon
http://www.solarassist.net/index.html
Impressive photo gallery of recent solar heating projects
Aesthetics 9, Content 7, Navigation 10, SEO Grade: 55

#4 Greenhead Solar, located in Spokane, Washington
http://www.greenheadsolar.com/index.htm
Excellent descriptions of solar panels.
Aesthetics 5, Content 8, Navigation 10, SEO Grade: 52

#5 New England Solar Hot Water, located in Duxbury, Massachusetts
http://www.neshw.com/default.aspx
Informative explanation of solar basics
Aesthetics 8, Content 8, Navigation 10, SEO Grade: 36

#6 Enviro Plumbing, located in Santa Monica, California
http://www.enviroplumbing.com/index.html
Extensive photo gallery including pictures of workers installing panels
Aesthetics 8, Content 9, Navigation 6, SEO Grade: 34

#7 Boston Solar Living, located in Medford, Massachusetts
http://www.bostonsolarliving.com/
Great information on tax credits and rebates
Aesthetics 7, Content 10, Navigation 6, SEO Grade: 29

#8 Creative Solar USA located in Canton, Georgia
http://creativesolarusa.com/index.php
Read an open letter from the company’s founder on why he went green
Aesthetics 9, Content 10 , Navigation 10 , SEO Grade: 18

#9 Aladdin Solar, located in Excelsior, Minnesota
http://www.aladdinsolar.com/home.html
One of the few websites to give estimated solar water heating prices
Aesthetics 5, Content 7, Navigation 9, SEO Grade: 24

#10 Solar Heating Services located in Berlin, Wisconsin
http://www.solarheatingservices.com/index.php
Read interesting case study of one their latest solar projects
Aesthetics 8, Content 8, Navigation 8, SEO Grade: 12

If your solar water heating installer website is on our top ten list, congratulations!

If not, contact us with a link to you website and we will review it for our future top ten lists.

There are many blogs on the internet devoted to the subject of renewable energy, and specifically to solar energy. In searching the web, the following six blogs are among the most unique and interesting ones that we found. Our ratings for each blog are also included.

#1
A particularly noteworthy solar energy blog is Solar Energy Rocks!. This blog primarily focuses on informing homeowners about rebates, grants, subsidies and tax credits available in all 50 states and the District of Columbia. The writers of the Solar Energy Rocks! blog believe that the reason that residential solar systems are not more prevalent is because homeowners are unaware of and misinformed about these incentive programs. Along with blog entries, visitors to the blog can click on their state to retrieve this information which is presented in an easy to understand format. In addition, Solar Energy Rocks! Has recently added two podcasts to their blog. This renewable energy blog can be found at http://www.solarpowerrocks.com/

Quality of content: 10
Applicability: 10
Aesthetics: 9
Frequency of posts: 10

#2
The Build It Solar is a relatively new renewable energy blog. The objective of this blog is to respond to questions that have been emailed to their website. The blog’s entries primarily deal with installation issues. Professional installers and do-it-yourselfers alike will benefit from the information offered by this blog. Recent posts regarding the building of a solar water heating system for $1000 and its continued performance will be of particular interest. Visit this blog at http://www.builditsolar.com/Blog/index.html

Quality of content: 10
Applicability: 9
Aesthetics: 9
Frequency of posts: 9

#3
Clean Technica is a renewable energy blog published by Green Options Media Production. This blog’s intention is to provide the general public with information on renewable energy options available and to describe actual applications of this technology. The Clean Technica blog is divided into categories, one of those categories being “solar energy”. Written for the lay person, blog entries to the Clean Technica blog are contributed by knowledgeable experts in the field. Visitors to the blog are encouraged to add their comments or questions, to which blog writers will respond. A recent blog post describes how a California company installed a solar power system in its warehouse facility. Other recent blogs include the U.S. Army’s solar energy system at a California base and the Energy Information Administration’s recent news of the significant increase in renewable energy in the U.S. Users may click on http://cleantechnica.com/category/solar-energy/ to be directed to the solar energy category of the Clean Technica blog.

Quality of content: 8
Applicability: 8
Aesthetics: 10
Frequency of posts: 10

#4
Powered By Solar Panels is the name of another solar energy blog. In addition to offering information about the benefits of renewable energy, this writer of Powered By Solar Panels is deeply concerned about the damage that the use of coal, oil and natural gas has done to the environment. Subjects of recent blog entries include a comparison between conventional and solar energy, an description of how solar energy works, how to generate solar house plans, and an explanation of why renewable energy solutions are necessary. Visit Powered By Solar Panels at http://poweredbysolarpanels.com/

Quality of content: 9
Applicability: 9
Aesthetics: 9
Frequency of posts: 8

#5
Get Your Green On is another renewable energy blog. The user will find recent posts pertaining to solar energy in the “green energy” category of this blog. The Get Your Green On blog is geared towards the residential home owner who is looking for increased energy efficiency in their home. Written in an easy to read style, subjects of recent posts include selecting a reputable renewable energy company, the installation of solar panels, the recent technological advancement of solar panels, the functionality of solar panels in cloudy winter months, how a solar energy system adds value to a home, how to build your own solar panels and more. The Get Your Green On blog is available at http://getyourgreenon.com/category/green-energy/

Quality of content: 10
Applicability: 8
Aesthetics: 6
Frequency of posts: 10

#6
The Residential Solar blog is published by The Solar Energy Source. The goal of this renewable energy is to educate the community, especially those uninformed, about how carbon emissions can be reduced for a cleaner environment by the use of solar energy solutions. User feedback is promoted with an email address for questions or comments. Recent entries this blog consist of the steps to take for a solar system installation, the top ten reasons for using solar panels and more. In addition to The Residential Solar blog, The Solar Energy Source also publishes several other renewable energy blogs. Visit The Residential Solar blog at http://thesolarenergysource.com/category/blog-installing-residential-home-house-solar-power-energy-electric/

Quality of content: 9
Applicability: 8
Aesthetics: 8
Frequency of posts: 6

In the last blog I mentioned calibrating the customers expectations by providing them with a simulation showing what they can expect from their system. Occasionally, a customer will not realize the savings they should and they expect you to fix it. Under the right circumstances it is possible to install a solar heating system and see only a small fraction of the savings that should be delivered…

One such situation is when the customer uses a solar tank to pre-feed an indirect gas or oil fired tank that operates as the back-up to their system. When using a boiler fed tank as the back-up, it is possible to intermittently not achieve the desired temperatures in the indirect tank thus requiring the boiler to cycle on. If this is in the summer time when the boiler is only used to service hot water (and not heat the house) this means that all of the losses and waste associated with starting up and shutting the boiler down is still there. How can we eliminate (or at least minimize) the intermittent cycling of the boiler when the solar tank is already hot?

One way to reduce the boiler cycling is to tie the solar tank together with the indirect tank in such a way that any excess heat in the solar tank is shared with the back-up tank thereby reducing the demand on the boiler. This can be accomplished simply with an extra connection between the tanks, a pump, a check valve, and a differential control. When the solar heated tank exceeds the temperature in the back-up (indirect) tank the circulator turns on and causes the two tanks to be mixed together in such a way that the heated solar water moves into the back-up tank. By tying the tanks together in this manner you have accomplished several things including: reduced the firing of your boiler increased the overall efficiency of the solar collectors (by keeping the tanks at a lower overall temperature) significantly reduced the customers overall energy bill in the summer time. made the solar system more robust and resistant to overheating (glycol systems)

While this technique will not hurt in any way it’s greatest benefit will be seen during the summer when the solar system is capable of producing the extra energy. It is possible to totally eliminate the customer fuel oil usage in the summertime with this scenario.

Click here for a sample drawing

When a customer has a solar heating system installed in their home they expect (and rightfully so) that their energy bill will drop pretty significantly. When a customer doesn’t see as much of a drop as they expect the question is why. One of the things that I encourage solar contractors to do is calibrate the expectations of their customers. Let them know what they should expect from their system. The best way to do that is to provide a simulation report . With this tool they can easily see what to expect from the system. Things keeps everybody on the same page about what the system should be producing.