Solar in the Dayton Area

dann-denny-residence-yellow-springs-ohioThough SunRock Solar is based in Blue Ash, Ohio–a suburb north of Cincinnati–we design and install renewable energy systems throughout southwest Ohio. We have completed projects in Oxford, Eaton, Tipp City, Kettering, Waynesville, and Yellow Springs. If you live in the greater Dayton area and are interested in learning more about solar for your home or business, give us a call. A few examples of our work in the greater Dayton area are described below.

SunRock has performed several installations in Yellow Springs, including one this past year at the Dann-Denny residence (featured in this Yellow Springs News article). The 5.2 kW solar PV installation was designed to provide about 80% of the couple’s modest electricity needs. At ages 94 and 79, the couple was particularly interested in leaving a legacy for the future.

SunRock installed a solar power system on the roof of a home in Kettering back in 2010 (photo here). In 2011, the roof was severely damaged in a hail storm and had to be replaced. SunRock removed the PV modules (which were NOT damaged by the hail) to allow a new roof to be put on, and then reinstalled the panels. The system is back in production and producing electricity for the homeowner.

A large farm and residence in Eaton was built with solar back in 2008. After several years on the property, the owners decided more energy was needed to meet the needs of the farm. In 2012, SunRock increased the capacity of the ground-mounted system to 31 kW (photo here). The owners are now considering the addition of a third solar power system to cover the electricity for a recreational cabin and pond aeration pumps.

In 2011, customers in Tipp City were interested in solar electric for their home, but didn’t want anything on the front roof of their south-facing house. So SunRock installed a pole-mounted system in the backyard (). This pole-mounted system has the added benefit of being seasonally adjustable to match the changing angle of the sun. The solar PV system has provided 91% of their electricity in the last 12 months.

Happy Solstice

happy-solticeThe long days of summer are here and solar production is at its peak for Cincinnati. We have plenty of sunshine here in the summer, but many people ask us if we get enough sun during the rest of the year to make solar projects feasible? The answer is, absolutely!  With thousands of solar power systems installed in southwest Ohio, there is no doubt solar works here.  The table below shows the percent of our annual sunshine we receive each month of the year.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
5% 6% 8% 10% 11% 11% 11% 11% 10% 8% 5% 4% 100%

Obviously our best sun conditions occur from March thru October, but even those cloudy months of winter provide some good solar days.

The sun’s angle above the horizon peaks on June 20, the summer solstice, and reaches its minimum angle on December 20, the winter solstice.

How does this play into the best orientation of solar panels?  Ideally when the sun is perpendicular to the surface of solar panels, the panels receive optimum sun and thus produce optimum power.  So to maximize production at the summer solstice, we tilt our solar panels at 26 degrees so the panel is at a right angle to the sun (26 + 74 = 90 degrees).  This would make production optimum for one day of the year, and suboptimum for the rest of the year.

But solar is forgiving and solar power systems which don’t have optimal siting still produce lots of solar power! There is a large “solar sweet spot” such that, even if the tilt and orientation of the panels towards south is not perfect, we take a relatively small performance hit.

What happens in practice is typically one of three things:

  1. We mount the solar panels flush with the roof of the home.
  2. We mount the solar panels on a fixed tilt mounting system on the ground.
  3. We mount the solar panels on a variable tilt mounting system.

In the end, if the modules do not face true south and are not tilted at just the right angle, solar still works and we still produce power.

Let’s discuss the three options above.

Option 1

We mount the solar panels flush with the roof of the home. This configuration provides the best aesthetics and lowest installed cost for most residential systems.  Typical roof angles are 18 – 45 degrees in the Cincinnati area, the most common being 18 – 26.6.  The systems perform well and the neighbors don’t think a space ship has landed on your roof.

Option 2

We mount the solar panels on a fixed tilt mounting system on the ground. This approach is often taken when there is available ground real estate and building roof structure or orientation is not conducive to a solar installation.  Here is a  solar carport constructed for a client in Cincinnati. The home has a large south facing roof, but it is encumbered by a large dormer and two large chimneys.  The carport array tilts at 15 degrees as a trade off to maximize solar production and minimize wind loading on the structure.  The array is producing 100% of the electrical needs of the home. At this  local farm we had plenty of real estate and freedom to line up the array to face true south with a tilt of 30 degrees (optimum for Cincinnati).  In general, ground mounted structures will be more expensive than roof mounted systems due to the cost of building the mounting system.

Option 3

We mount the solar panels on a variable tilt mounting system. This allows the tilt angle of the modules to be adjusted (typically monthly) to follow the sun’s seasonal elevation changes.  This approach adds some cost due to the increased complexity of the structure, but the benefits are many. It is easy to mow and trim around the structure, solar production is maximized, and less real estate is needed for the array. SunRock Solar installed a  seasonally adjustable pole mounted array in Reading, Ohio. This site is interesting as it has some late afternoon shade so the array was oriented to face slightly south east rather than true south.  This actually improved the system performance by approximately 5% over a true south facing array.

To wrap up, there are many factors which contribute to the performance and aesthetics of solar power systems.  Each situation is different. By taking the time to analyze and discuss options with its customers, SunRock Solar can deliver a power system which melds aesthetic and performance expectations, with the reality of site conditions. Solar works well in Cincinnati!

SunRock Solar Installs More Commercial PV Systems

sunrocksolar-panel-arraySunRock has recently installed two more commercial systems. A 51 kW direct tied photovoltaic array was installed on the  roof of the locomotive shop at the CSX rail yar in downtown Cincinnati.  The system at CSX allows the company to take advantage of financial incentives and offset power purchase from the local utility.

For more information about financial incentives available in the state of Ohio, click here.

Grabill Heating and Plumbing decided to install a photovoltaic system to offset the electrical costs associated with running its business. It was a two-phase process with the first panels installed in 2011. It is a 19 kW direct tied PV array. The solar panels mounted on the showroom and warehouse and now produce 95% of Grabill’s electrical needs.

To see photos of other commercial installations completed by SunRock Solar, click here.

Are you wondering if a solar installation is right for your business?  Call SunRock Solar at (513) 766-6025 to discuss available financial incentives and how they can make solar affordable for you!

Interview with SunRock Customer

toyota-prius-with-solar-systemHarvey P. of Yellow Springs Ohio hired SunRock Solar to install a photovoltaic array in his backyard using a seasonally adjustable pole mount system. The installation was completed on May 3, 2011, so the system has been in production for about a year.  We interviewed Harvey about his panels and the pole mount system.

How big is your system?

Fifteen 230-watt modules for a system rating of 3.45 kW.

What percentage of your utility is being covered? How much have your utility bills gone down?

I am covering 100% of usage, but we were not big users. Our electric bill is now $10.00 per month, covering the first 100 kWh, which I never use.

Now that it has been running for awhile, have you figured out how long it will take to pay it off?

Very uncertain, as it depends on electricity rates, SREC values, and the value of my power uses (e.g. the use of solar to power my plug-in Prius displaces gasoline charges)

How many SRECs have you produced?

Slightly less than 4 MWh at this point.

You decided to use a pole mount system. Why didn’t you put the panels on your roof?

More shading from neighbors trees than was the case with the pole mount.

Why didn’t you use a regular ground mount system?

I wanted the option of “following” the sun during the seasons, and also the pole mount left more gardening space than a ground mount would have.

Do you think the pole mount system has helped your production?

Yes, based on a comparison with a roof-mount array located nearby. The steep winter tilt also helps prevent snow build up on the panels.

Are you satisfied with the production? Yes.

Is the tilt mechanism easy to adjust?  Yes, very easy.

How often do you need to adjust it?

I usually change the setting twice a month, and sometimes more often if I am showing the installation to someone.

Have any issues or problems developed?  No.

Have you had any major storms hit your area? Hail, or high winds?

There has been some small hail and fairly high winds.  The hail caused no visible damage and the wind caused the array to shake a bit, but not enough to cause worry or damage.

Are you satisfied with the work that was performed?  Very much.

What other things do you do at your house to reduce your energy costs?

We have new appliances, all energy star, and most of our lighting is with CFLs.  We are replacing our windows to decrease air conditioning load, the only possible use that would exceed our production enough to use our “banked” production.

Are the panels producing enough energy to handle your house and charge up your electric car?

We have a plug-in Prius, and easily have the capacity to cover it.  (about 4 kWh for a full charge.  It is not used every day.)

Do you monitor your usage more now that you have panels installed? Has it made you more aware of what you are using?

No, I have kept a spreadsheet of usage for several years.  But I do enjoy following the solar production using the online monitoring.

Are you glad that you had solar panels installed at your house?

Yes, indeed.

SREC Data Collected from SunRock Solar Customers

solar-panel-on-roofThe following data has been collected from current SunRock Solar customers to show what each has made by selling their SRECs produced by their installed systems.

We were able to collect information from 13 out of 21 of our residential PV customers.  Four systems are still waiting for state certification, and data is not available for the others at this time.

It does not reflect the SRECs that our commercial customers have sold, nor does it reflect those that have contracts for their solar hot water systems.  Contracts are no longer available for SHW customers.

The SolSytems customers have all signed contracts so they have received the same amount for each SREC.  SREC prices range from $200.00 to $303.00.

The SRECTrade customers put their SRECs up for auction when they are produced and their sale prices vary.  SREC prices range from $265.05 to $372.93.

Customer 8 puts their SRECs for sale on the GATS billboard and companies deal directly with them to buy the SRECs. These SREC prices range from $325.00 to $385.00, which is the most anyone has received.

Data was collected through the end of February 2012.

Array size -KW KWh expected Installation Date In production Market Total SRECs sold Average Price /SREC Total $ from SRECs
Customer 1 3240 3649 6/18/10 20 months SolSystems 6 $303.00 $1818
Customer 2 4836 4643 8/6/2009 42 months SolSystems 13 $200.00 $2600
Customer 3 2760 2804 5/15/2010 21 months SolSystems 5 $270.00 $1350
Customer 4 4620 4974 1/25/2011 12 months SRECTrade 4 $265.05 $1060.20
Customer 5 4600 4978 12/31/2009 37 months SolSystems 10 $303.00 $3030
Customer 6 3450 3809 5/3/2011 10 months SRECTrade 2 $358.52 $717.03
Customer 7 3220 2707 2/17/2011 12 months SRECTrade 1 $353.40 $353.40
Customer 8 8800 9822 10/26/2010 15 months GATS billboard 7* $375.00 $2635
Customer 9 6300 7/17/2009 31 months Duke 18 $325.00 $5850
Customer 10 9680 11616 3/30/2010 20 months SolSystems 24 $303.00 $7272
Customer 11 2272 2491 10/2/2009 40 months SolSystems 5 $303.00 $1515
Customer 12 5280 5735 2/15/2011 13 months SRECTrade 3 $265.05 $795.15
Customer 13 4950 5211 12/31/2010 14 months SRECTrade 5 $369.02 $1845.12

 

*Customer 8 has produced four additional SRECs but has not put them up for auction yet.

Installation of Solar Panels Using a Pole Mount System

solar-panel-on-pole-of-mount-systemSunRock Solar has started using pole mounts to install photovoltaic systems for some of our customers.  Pole mounts are a valid option when there is a small amount of roof space to install an adequate number of panels, the roof line is east/west, or there is too much shading to justify an installation.  The poles consist of a single pole with a crossbar where the solar panels are mounted.   There are two different sizes of poles that can hold either ten or fifteen panels each.  Because everything is mounted on a single pole, the footprint of each pole is minimal.

We buy the mounting system from a company called True South.  The company is located in Ohio and the poles are also manufactured here.

Another feature of these poles is that each pole has a hand crank, at the ground level, that can tilt the panels.  In this way, the panels can be adjusted to give an ideal tilt for each month of the year.

To see pictures of the installation of a pole mount system in our gallery, click here.

Great Loans for Solar Installations

solar-on-pole-mountThere are two loan programs that are available to our customers to help offset the cost of installing solar panels.  One is a HIP loan and is available for Hamilton County residents and one is the EcoLink program which is available for Ohio residents.

1. HIP Loan (Hamilton County’s Property Improvement Program)

This program allows Hamilton County residents to borrow money to repair or remodel their homes or rental property at interest rates 3% below the lowest rate a bank would normally offer.

Solar panels qualify!

  • Loans at 3% below market rate, 5 year term – only one outstanding loan at any given time
  • Available in participating Hamilton County communities.  Milford City does not participate.
  • No Income Restrictions or limits (must be able to meet bank’s credit requirements)
  • Loans are capped at $50,000
  • For one-family, or two-family, and commercial properties valued up to $350,000 (based on Hamilton County Auditor’s appraisal)
  • All Property taxes must be current
  • Owner-occupied and investment dwellings qualify for the program
  • There is no property value limit on multi-family dwellings (three or more units)

Most types of permanent repairs or improvements are allowable. The HIP loan is structured as a home equity loan, secured by a second mortgage on the property.

Most of the banks are unwilling to approve the loan if they cannot obtain a secondary lien on the property. However, you should discuss your options with a participating lender.

Five banks participate in the program-Fifth Third, First Safety, Key Bank, North Side bank, and US Bank.  Rates vary from bank to bank.  Closing costs vary from bank to bank.  It is worth it to shop around.

Traditionally, the lowest interest rates have been given by Key Bank and US Bank.  Shelley Cummings(513-533-7716) at Key Bank is very knowledgeable about the program.

To find out more, check out the website at http://www.hamilton-co.org/hc/hc_hip.asp

Contact Information
Jay Springer, “HIP” Coordinator
Hamilton County Department of Planning and Development
138 East Court Street, Room 807
Cincinnati, OH 45202

Phone: 513.946.4459

Fax: 513.946.4475

2. EcoLink Program

ECO-Link offers a reduced interest rate on qualifying loans to homeowners completing energy-efficient upgrades, installing renewable energy products or weatherizing their homes

Solar panels qualify!

  • ECO-Link is a partnership between the State Treasurer of Ohio and participating state banks.  Find a list of the participating banks on the website
  • Provides a 3% interest rate reduction for five or seven years on  bank  loans
  • Must be used to complete energy-efficient upgrades in your home.
  • Must be an Ohio Resident
  • The maximum loan amount is $50,000.
  • There is no limit on property value to qualify for the loan
  • A homeowner can opt for a seven-year rate reduction if the loan is for more than $25,000.
  • The homeowner must use at least 50% of the loan proceeds for the installation of qualifying energy-efficient products; the other 50% of the loan can relate to other home improvement projects.
  • There are no fees for the preparation, processing, reporting or monitoring of any ECO-Link application to the Treasury.
  • Eligible products and projects include, but are not limited to:
    washing machines, dishwashers, furnaces, hot water heaters, freezers, refrigerators, heat pumps, air conditioners, windows, doors, roofing, insulation, septic tanks, boilers, programmable thermostats, geothermal units, solar panels and small scale wind turbines.

To find out more visit their website at http://ohiotreasurer.gov/ecolink

Contact the Ohio Treasury, Department of Economic Development via e-mail at ecolink@tos.ohio.gov call (614) 466-6546 or toll free at (800) 228-1102

The 9th Annual Green Energy Ohio Tour

solar-panel-as-carportMark your calendars for the Green Energy Ohio Tour which is taking place this year on Saturday October 1st and Sunday October 2nd.  This year they have changed the name from the Solar Tour to the Green Energy Ohio Tour.  The new name more accurately describes the tour which features not only solar but tour sites with wind, energy efficiency, biomass, and other green energy technologies.  This is a free statewide event organized by Green Energy Ohio.  The 2010 tour was the largest in the nation.

SunRock Solar is well represented this year with 12 of our installations on the tour.  The website to build your own tour is up and running although new sites may still be added.  It is pretty slick.  Just put in the region that you would like to visit and the time, and it will build a custom tour for you including directions and pictures of each of the installations.  Click here to build your custom tour.

If you are thinking about adding solar to your life this is a unique opportunity to talk with owners who are living and working with green energy technologies.  Come learn how friends and neighbors are combating rising energy costs, slashing utility bills, utilizing incentives and tax credits.

The Solar Tour is Coming

solar-panel-as-carportMark your calendars for the 2011 Green Energy Ohio Tour (previously known as the Solar Tour.)  This year the statewide event will take place October 1st and 2nd.  SunRock Solar will be well represented with 10 houses on the tour.  The GEO website with more information will be available early September.  You will be able to create your own tour by entering your zip code, and the type of solar installations you are interested in viewing.  Be sure to check out some of the exciting SunRock Solar installations.

We will be posting more information here as it becomes available.

Factors Effecting Photovoltaic System Performance

solar-on-pole-mountA variety of factors influence the performance of photovoltaic system production.   System owners want to get the most for their money when they install solar panels on their home or business.

Location, location, location

One of the most important factors in system performance is the location of the solar array.  Location has three important components:

  1. Array azimuth (orientation with respect to true south)
  2. Array tilt (orientation with respect to horizontal) and
  3. Shading.

Array Orientation
In southwest Ohio we want the solar array to face south.  The sun rises in the east and sets in the west and peaks in the sky at solar noon each day.  While it is possible to mount modules facing east, west or even north the performance penalty increases the further away from true south the array faces.   For rooftop mounting on pitched roofs the best approach is to mount the modules parallel to the roof.  This provides the best aesthetics, though it does compromise performance to the extent that the roof does not face true south.    For flat roof applications there is opportunity to orient the modules irrespective of building orientation, and a variety of commercial mounting systems make this an easy approach.  So how much does array orientation effect system performance? To view the graph comparing system performance vs. array orientation click on the following link.

Figure 1- System Performance vs. Array Orientation

The chart shows that if the array faces south + 30 degrees it will still produce 97-98% of the optimal system output.  In Figure 1, 90 degrees represents an east facing array and 270 degrees represents a west facing array.  As you can see from the chart these extremes reduce the array performance by almost 20%.  So south facing arrays work best but if that does not match your roof line there are other options with predictable outcomes.

Array Tilt
A photovoltaic module works best when the sun strikes it at a 90 degree angle.  Most residential and small commercial solar arrays are installed with a fixed tilt (more on tracking arrays later).  Since the angle of the sun (as measured from the horizon) changes throughout the year, what is the best angle to mount the modules to maximize system performance?  Assuming we have an array which faces true south the following chart provides the answer (for southwest Ohio).  To see the graph thaat compares tilt and system performance, click on the following link.

Figure 2 – System Performance vs. Array Tilt Angle

The chart shows that for our area, 30 degrees is the nominal tilt angle for a photovoltaic array.  If we mounted the array horizontal to the ground or flat we would still achieve 88% of the optimal production and if we mounted the array vertically facing south we would achieve only 58% of our optimal production.   Most pitched roofs range from 18 – 45 degrees and these will achieve 95+% of optimal system output.  Again for flat roofs the mounting systems allow us to select the angle of tilt for the modules.

Tracking Arrays
There are mechanical solar tracking systems available that attach to the panels and track the sun throughout the day to maximize the hours of sunlight.  In general these systems add mechanical complexity (read installation and maintenance cost) which in general outweigh the performance improvements.  Trackers are typically only being implemented for large utility scale projects.  SunRock recently installed a pole mounted system which orients the array to face south and has a hand crank that is turned to adjust the array tilt to follow the seasons.  This system improves system performance by approximately 5% annually with no expected increase in maintenance costs.

Shading
Photovoltaic modules are very sensitive to shading.  SunRock performs a shading analysis for each site during the project evaluation and bid preparation.  This allows us to provide an accurate estimate of the system’s expected performance.   Shading occurs from surrounding trees, buildings, chimneys, dormers, and other structures, so a careful evaluation of the site needs to be performed prior to estimating production data.

If you have a yard full of trees and a roof full of shade, then your rooftop may not be a good candidate for solar.  There are other options though.  Solar panels can be installed on ground mounts, top of pole mounts, carport structures, etc.  For some possibilities check out our project photos.

There are also new micro-inverter and DC optimizers which can help mitigate shading issues at the site. These are deployed based upon specific shading issues at the site.