Presentation Tomorrow


Going Solar-Presentation by Carl Adams

Time:  August 19, 6-7:00

Where:  Marvin’s Organic Gardens, 2055 U.S. State Route 42 South Lebanon,  OH

Learn about photovoltaic (solar electric) and solar hot water applications for residential and commercial buildings, as well as the grants, tax credits, and loan programs currently available to fund these projects.  Carl will also highlight projects installed by SunRock Solar.  Find out how you can incorporate solar energy into your home or building.

Energy Vampires

There Are Vampires Among Us

Before installing a solar power system for your house, homeowners should become more aware of their household energy use,  and try to cut back whenever possible.  There are many little things that you can do to improve your energy efficiency.  One of these involves controlling your vampires.

What are Energy Vampires?

Vampires are not only in romantic movies.  As you walk through your dark house at night, the vampires will light your way.  Energy vampires are electrical products that have a stand-by mode and cannot be completely switched off unless they are unplugged.  They suck small amounts of energy 24 hours a day.  Some examples of vampires include cable and satellite boxes, digital clocks, and video game consoles.  The wall chargers for cell phones, power tools, or hand-held vacuums will use energy even though the device has finished charging.

The Lawrence Berkeley National Laboratory has studied the energy consumed by these gadgets.  Although the energy used to power these devices is relatively small, when all the household products are added together, the standby power can amount to 10% of the residential energy use.  Here is a list that they have compiled that shows different products and their standby energy usage.

What’s a Mortal to Do

Unplug–Although it is not always practical, the best way to save energy is to unplug the devices when they are not in use.   For something like digital clocks, or cable systems, this is not always practical because of the time that it takes to reboot.  If you are going to be gone for long periods of time, it is worthwhile to unplug everything.   Items like cell phone or power tool chargers can be easily unplugged when the item has finished charging.  The trick is remembering that they are there.

Use Power Strips–Plug your items into a power strip that can be turned off when you leave the house, or go to sleep.  Power strips will help save time where you have multiple gadgets plugged together.  There are even smart power strips available that will turn themselves off when the items are not being used.

Turn on the Energy Saving Features–Some devices, like personal computers, have energy saving devices built into them.  Take some time to look for the settings, and set them for the lowest possible energy usage.

Look for the Energy Stars–When buying new appliances or gadgets, always look for energy star labels.  These don’t just come on big appliances anymore.  Even phone chargers, and ceiling fans now come with a rating.  The energy star website has a big list available.  Gadgets with an energy star certification mean that the products have reached a high level of energy efficiency and have met requirements established by the Environmental Protection Agency.

Controlling your energy vampires is a good place to start when trying to cut back on your household energy usage.


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What are SRECs?

solar-panel-on-rooftopsSREC stands for Solar Renewable Energy Certificates or Solar Renewable Energy Credits.  Some states, like Ohio, have a Renewable Portfolio Standard (RPS) that requires electricity suppliers to secure a portion of their electricity from solar generators. An SREC is created for every megawatt-hour of solar electricity created.

1 SREC = 1,000 kWh of solar electricity = 1 MWh of solar electricity

If you have a 10kW PV solar system you will receive about 1 SREC per month or 12 SRECs per year.  The amount that is paid for each SREC is determined by the market and subject to the constraints of supply and demand.

SRECs are sold separately from the electricity and represents the solar aspect of the electricity that was produced.  Sale of SRECs is intended to promote the growth of distributed solar by shortening the time it takes to earn a return on the investment.  SRECs help the states reach their Renewable Portfolio Standard , and help the PV owners see a quicker return on their investment.  Overall they help promote the growth of disttributed solar systems throughout the states.

Sol Systems Discontinues Solar Thermal Offer

solar-water-systemA message was received on May 17, 2010 informing SunRock that Sol Systems is temporarily discontinuing its solar thermal SREC program for all states except Washington DC.  Sol Systems was the only company accepting SRECs from solar hot water systems from our Ohio customers.

According to their email, there have been significant changes in the solar thermal market.  Exelon, a large Mid-West utility, recently imported a 10MW project into the Washington DC SREC market, which is the only market to currently accept solar thermal systems.  This Exelon system will produce around 11,000 SRECs annually, which is more than 4 times the total size of the overall market. This means its SRECs will completely overwhelm the demand for SRECs in the DC market.

In new markets like this, a significant oversupply of SRECs will decrease SREC values dramatically.  It may be that in the near future out-of-state SRECs will be worth nothing in DC. Because Sol Systems have utility-backed customers, they should be in a good place.  Customers working with Sol Systems competitors in the spot markets or who have not backed up their portfolio (and there are many of both) probably are not.

It appears as if the SunRock customers already registered with SolSystems will be unaffected by the discontinuation.  We will continue to monitor the situation and to keep you updated.

Micro Inverters

residential-pv-systemsSunRock Solar’s final install for 2009 was a 4.6 kilowatt (kW) solar array system for the Loy family in Butler County.  The Loy’s home site is a beautiful setting, but some of the tall trees surrounding the home also posed a shading issue that influenced our decision to use the Enphase microinverters. The installed system consisted of twenty Sharp 230 Watt modules and twenty Enphase microinverters.

The Enphase microinverters used on this project are different from string inverters that are typically mounted inside a building and tied to a string of several modules. The microinverters attach to the module mounting hardware underneath each solar module and convert the direct current (DC) electricity from each module into utility grid compliant alternating current (AC) electricity.

Shading on solar arrays causes significant power losses (i.e. $$$ lost), especially for batch inverters.  For batch inverters, if only one module is shaded on a set of connected modules, the power output for the entire set of modules is reduced.  The Enphase microinverters (pictured) improve the performance of the system because shading of one module does not affect other modules. System performance on arrays with microinverters can be 5 – 25% when compared to a batch inverter.

The Loy’s also opted for the Enphase system monitoring solution, which collects and transmits performance data from each solar module to the Enphase Enlighten website. The Loy’s can monitor the performance of the solar array in real time,  or look at performance for the week, month, or year to date. Here is a link to the system on the Enphase Enlighten website:  Loy System Web Based Monitoring.   The time lapse playback for the day or week is an impressive representation of the system’s power production.   

The above picture was taken just after one of the major winter snowfalls.  The modules covered with snow are producing little to no power, but those modules that are clear of snow are producing power.  For a traditional string inverter setup the power production of all modules connected to those snow covered modules would be impacted.

The Loy’s site has some shading issues, which makes the microinverter system the logical choice for this project. This new technology gives customers with similar shading issues the opportunity to have a solar array that’s power output is not significantly reduced due to the shading.  If you think your roof space is not a good candidate for solar maybe an Enphase microinverter system is the answer for you!