Sunday, April 29, 2012

Drip Irrigation and Rain Water Harvesting

Over 95 percent of the water irrigation methods used in Texas are spray based, and of those systems, about 92 percent are not properly maintained. In North Texas, given our susceptibility to drought, the need for an alternative to landscape watering becomes more compelling. The Texas AgrLlife Research and Extension Center offers a series of classes on water conservation demonstrating how easy it is for homeowners to set up their own drip irrigation and rain water harvesting system. During a two-hour class at the extension center, located at 17360 Coit Rd., Richardson, Texas, participants learn about the different types of available commercial tubing, the proper way to lay out an irrigation system to maximize water pressure and evenly distribute water in the covered area, along with different components needed for the system such as a backflow preventer, splitter, filter, pressure regulators, tubing adapters and tubing to set up one’s own system. The class outlines the steps needed to convert an existing sprinkler system into a drip system. In addition, Texas AgriLife offers classes on rain water harvesting. Every inch of rain falling on the roof of a 2,000 square foot home collects over 1,200 gallons of water. Harvesting this water with rain barrels connected to rain gutters makes practical sense. Participants of the class learn how to make a rain barrel and properly install a rain barrel harvesting system at home. Classes in drip irrigation and rain water harvesting are held at the Texas AgriLife Extension Center through the summer and fall. Registration is online at Although we enjoyed a relatively lush spring, North Texans realize how precious water is in our community. Water management practices through drip irrigation and rain water harvesting help reduce wasting our existing water supply from lakes and reservoirs in our watershed. The Sustainability Steward

Tuesday, April 10, 2012

Solar Energy in Plano

By the end of 2010, there were over 40 GWp of total photovoltaic (PV) solar energy capacity installed in systems around the world - that's over 40 billion watts peak. Preliminary data at the end of 2011 indicate this number increased to over 65 GWp. Germany continues to lead the world with about 40 percent of installed solar energy capacity (over 25 GWp).

At the end of 2010, the United States had installed about 2.2 GWp (2.2 billion Wp) of PV solar. Preliminary data for 2011 indicate that we now have over 4 GWp installed, a very sizable increase in just one year. Closer to home, Texas added about 47 MWp (47 million Wp) of PV solar installations in 2011 bringing the cumulative installed capacity to about 80 MWp.

Texas exceeded its overall Renewable Energy Portfolio Standard (RPS) requirement passed by the Texas Legislature by installing over 10 GW (10 billion W) of wind energy. (The original RPS passed in 1999, with an update in 2005.) However, the 2005 legislation included a target for the state to reach 5 million W of non-wind renewable energy. As solar energy continues to expand all around the world and the US, we have further opportunities in Texas to grow our use of solar energy. (See the Live Green in Plano blog posting from March 21, 2012 - Solar Energy in Texas.)

So how does this growth in solar energy around the world and the US impact residents in Plano? What’s in it for us? How much electricity is produced today in Plano from PV solar? To achieve the target of 500 MW across Texas, how much electricity should Plano be producing from PV solar to contribute our share?

At the end of 2010, it is estimated Plano had about 240,000 Wp of PV solar installed in 35 to 40 residences and businesses around the city . If we use the Texas RPS goal of 500 MW non-wind, and assume we should target this non-wind as solar, we can make some calculations to determine a few targets for Plano.

If we use population as our metric, Plano has approximately 1.06 percent of the state's population. So one percent of the 500 MW target means Plano’s target is 5.3 MWp from PV solar to contribute our share of the overall Texas RPS target. If we assume the average PV solar installation is 5,000 Wp (which is a typical size residential PV solar system across the US), then we would need approximately 1,060 of these average PV solar installations in Plano to achieve 5.3 MWp. Real estate data on the internet indicates Plano has approximately 60,000 single family homes. To achieve the target of 5.3 MWp of electricity generated from PV solar, we only need about 1.8 percent of our existing homes (1,060/60,000) to have this 5,000 Wp PV solar system installed and operational.

Where is more information about PV solar installations for your home? Generally, electricity is distributed to residents in Plano by either Oncor or CoServ. If your home is serviced by Oncor, then you can find out about solar program information from their website -

Check out a few examples of solar programs offered by retail electric providers operating in Plano in the Oncor serving area by visiting their websites:

If your location is serviced by CoServ, check out information about PV solar at their website -

Need more info about promoting the use of solar power generation in Plano? Contact me!

1st paragraph and 2nd paragraph
REN21 Renewables 2011 Global Status Report -

U.S. Solar Market Insight: 2011 Year-in-Review Report - Executive Summary -

3rd paragraph
Texas State Energy Conservation Office - Texas Renewable Portfolio Standard -