Monday, August 29, 2016

Calling all architects! Help us recover from “Pointy Roof Disease”

Ok, this post is from the perspective of a rooftop solar energy advocate, but hopefully it will spark some serious discussion and eventually design changes!

Let’s take a look at what has become of roof designs of new homes in North Texas. Let’s take a look at solar PV technology. And, let’s take a look at the recent “solar-ready” provision in the optional section of the 2015 International Residential Codes. Ultimately, we need help from architects to develop innovative ways to couple new roof designs with solar-ready features to help North Texans on their path to “net zero” homes.

First, what is “solar-ready”? A new solar-ready home is designed and built to prepare for the most efficient use of solar PV (photovoltaic) energy panels in the future. Homeowners have the choice of installing the panels immediately after construction, or waiting to exercise this option at another time. There are several factors that make a home solar-ready:

  • installation of appropriate electrical systems
  • adequate south-facing roof space
  • angle of the roof to the position of the sun

Specific details are available in Solar Ready Provisions, Appendix U of the 2015 International Residential Codes. Building a solar-ready home saves time and money. It enables a homeowner with an energy efficient home a future path to “Net Zero”. This means its solar PV system generates enough electricity during the year to offset all or nearly all of the home’s electricity consumption for the year.

According to Wikipedia - A roof is part of a building envelope. It is the covering on the uppermost part of a building or shelter which provides protection from animals and weather, notably rain or snow, but also heat, wind and sunlight.

One of the great things about rooftop solar PV is that it can leverage the normally unused space of a home’s roof. It can allow the roof to serve its normal function as described above, and a second valuable function to capture light energy from the sun to help power our home’s electricity needs.

Now here is the rub. For whatever reason when it comes to roof designs, it seems that the one with the most points and angles wins. Over time, it seems a bit like the spreading of “Pointy Roof Disease”. All these angles and all these points, especially when placed on the south facing roof, make it very difficult, if not impossible to have a solar-ready home.

Take a look at the following photos of North Texas roofs. Ask yourself, what is the purpose of the angles/points? What is the function?

Fig 1 – Three main roof surfaces. For a south facing roof surface, having just one main surface would greatly facilitate cleaner installation of solar PV.

Fig 2 – Five (or six) roof surfaces. Reducing this to maybe two surfaces would greatly facilitate cleaner installation of solar PV.

And these that follow seem to be competing to win the prize for the MOST points and angles. If these represent the south facing roof surfaces, then these roof designs virtually eliminate the potential for a productive rooftop solar PV installation.

I wonder - what is the function of this “extra” triangle protrusion on this roof?

And what is the function of this double peak with the trough that would be a great place for roof leaks to form?

So which of these do you think wins the prize for the MOST points and angles? And which one has any chance of installing rooftop solar PV in the future and achieving net zero? Sadly, these roof designs are severely limiting the future potential of net zero homes.

The goal of this blog post is to raise awareness and start a dialog to promote solar-ready home designs! Share it with your friends. Reach out to encourage architects to begin providing creative solutions and tackling the transition to solar-ready home designs. Tell homebuilders that you want to buy homes that are solar-ready! North Texas uses more electricity per residence than any other part of the state. Combining new energy efficient home designs with solar-ready home designs creates a sustainable path to the use of clean local distributed energy and reducing the strain on our electric grid for all of us!

Calling all architects! Help us recover from “Pointy Roof Disease”! Bring on the age of solar-ready homes! Comments welcome and encouraged!

Shine On!
Plano Solar Advocate (LH)

Thursday, July 21, 2016

What is “roofless” solar?

Our volunteer group advocates for clean local solar energy.  Being able to generate energy from rooftop solar, in the location where you consume the energy, is an ideal solution.  However, it might not always be possible. The concept of “community solar” or “roofless” solar is proving to be the next best thing. While the availability of community solar options has been expanding across many states, it is only now becoming available in Texas.  Below is the recent story from one of our volunteers in Plano.

Our Path to "Roofless" Solar
When solar tax credits first appeared, my husband and I had an installer evaluate our roof.  The prognosis: too many trees, too much shade.  We enjoy our trees and decided to settle for an electric provider offering green energy.  Fast forward to 2015. We lost a 40 year old silver maple in the backyard and began to reconsider solar.  It didn’t take long to realize the roof exposure that opened up was still not optimal for collecting rays.

A presentation at a Plano Solar Advocates meeting introduced us to the concept of community solar and that sounded like a perfect solution.  Community solar is also known as “roofless solar” and involves an offsite solar farm that services a community. Research showed many advantages: no rooftop limitations: orientation, multi-family housing, shading, or roof quality; clean, locally-sourced energy production that can support and strengthen the grid; motorized tracking devices that position the panels to catch the most rays boost energy production.

Cypress Solar Farm is a new solar farm located southwest of Fort Worth in Walnut Springs.  The energy produced through its acres of solar panels is delivered into the electric grid operated by Oncor.  MP2Energy works with Oncor to deliver that energy to our home through a five year contract at a cost-effective rate.  We want to support clean energy in North Texas and community solar is making that possible. For more information, check out:

Thanks to our volunteer DB Solar Advocate for sharing this story!

Share your solar stories and "TALK UP" clean local solar energy!
Shine On!

Wednesday, April 20, 2016

Talk Up Solar Energy Where You Live!

Whether you live in a single-family residence or a multi-family community, there is probably a great opportunity to take advantage of sunlight that falls on your roof to generate clean local electricity!

For example, if you live in a single-family home in North Texas, check out Go Solar at Home to learn about rooftop solar, do a little homework, and if you are interested, enroll to obtain quotes from local solar installation companies.

If you live in a North Texas multi-family community, check out the properties below that already have rooftop solar PV systems installed! And every year, more and more are adding solar PV panels to provide local clean energy from the sun! If yours currently does not have solar panels installed - talk it up! Ask then when they plan to add panels and how you can help speed up the process!

Summit Parque,
12777 Merrit Dr., Dallas, TX 75251

Oak Lawn Heights,
2600 Arroyo Ave, Dallas, TX 75219

The Alista (Flats & Villas),
10028 Royal Lane, Dallas, TX 75238

La Jolla Terrace,
8900 Randoll Mills Rd, Ft Worth, TX 75251

Please let us know when you learn of other multi-family properties around North Texas that have "Gone Solar", and Talk Up Solar Energy Where You Live!

Shine On!
Plano Solar Advocate (LH)

Monday, January 18, 2016

Valuing Distributed Generation

The Texas State Energy Conservation Office released a report in December 2008 titled, "Texas Renewable Energy Resource Assessment"(pdf version of full report). Below is an excerpt [bracketed by asterisks] from the "Summary and Conclusions" chapter, in the subsection "Valuing Distributed Generation" that remains relevant today. It describes the importance and strategy for valuing distributed generation.

Valuing Distributed Generation

Small renewable energy generation systems located at the point of use capture the benefits of renewable energy while reducing utility costs. One study identified 19 key values of distributed generation, including values associated with energy generation, available capacity, transmission and distribution cost deferrals, reduction in system losses, reactive power, improved system resiliency, increased reliability, electricity price protection, and pollutant and greenhouse gas emission reductions. (Reference)

Examples of distributed renewable generation include rooftop solar water heaters and solar electric systems, small wind energy generating systems, and ground-source heat pumping systems. Most distributed generation systems produce enough energy to meet a portion of a home’s or business’ energy needs, reducing the amount of electricity purchased from the utility. Such reductions are equivalent to reductions in consumption derived from efficiency or conservation measures. Some technologies at times produce more than enough energy to meet a home’s or business’ energy needs, and during those periods export electricity to the grid. Capacity, exported energy and other key values provided by distributed generation should earn the generation owner compensation at a fair value. If efficient, transparent markets are unavailable or impractical to enable distributed generation owners to be compensated for the value they create, then that value should be made available.

Strategies for Valuing Distributed Generation
  • Incentive programs. Policies and programs supporting adoption of distributed renewable generation, including the efficiency programs offered by Texas electric utilities, should recognize and account for the total value of distributed renewable energy delivered to the utility and its ratepayers.
  • Interconnection policies. Policy makers should encourage adoptions of consistent interconnection requirements and processes by all Texas electric utilities.
  • Net metering. All customers with distributed renewable generation should have the opportunity to earn a fair price for energy outflows without having to switch retail electric providers or renegotiate the terms of existing retail energy purchase contracts.
Shine On!
Plano Solar Advocate (LH)