Solar Power Engineering Services
Our focus is the creation of your project's permit-ready construction plans
Why ECO for Solar Structural Design?
Experience, Capability, Size
Eco-Holdings Engineering has completed energy engineering for Residential solar PV arrays from 2 kW to 7 kW and Commercial solar PV arrays of up to 145kW.
ECO's solar power engineering includes general consulting, site planning, & structural design. As a result ECO has contacts with suppliers, installers, commercial roofers, and electrical contractors. ECO can coordinate information from all services to create a construction ready solar design.
ECO can join your project's Distributed Solar Power implementation team. Contact ECO at 713-377-4209.
Consulting is Information with Experience.
Read ECO's overview of our engineering for solar energy systems below. Contact ECO when you are ready to see how our experience might help your sustainability project.
Solar Energy Consulting We support solar energy with consulting and design engineering services.
For a new project or existing site located on a sunny, unshaded site in Texas, solar energy should always be considered.
But what specifically will be required for solar array design to work on at your site? We help answer those questions by providing detailed engineering.
Commercial Solar Array Supportfor Greater Houston Galveston Solar PV Array Installations
Solar array installation based on ECO mounting bracket design using Autodesk Revit Structure and Revit MEP software
Our work is under or behind the designers concept. We develop Revit based structural 3D analytical models like this to support a designer's concept. We consider wind loads, component weights, material types and strengths, constructibility, construction sequencing and system durability.
This solar awning array required a detailed review of the existing structure, masonry connection testing, and the design of a custom awning structure. ECO provided all design engineering and construction drawings including fabrication drawings of all components. This awning array is part of one of the largest public school solar electric power installations (~150 Kw) in North America.
The type of project begins with the structural review or as-built plans and then the inspection of an existing structure, This helps to determine if it can properly support the solar equipment while also resisting wind forces on the solar panels. Next, we create structural drawings for each location showing layouts. These show orientations of each solar array, all structural connections, and detail all part types and quantities. 
Solar PV arrays in high wind areas have many structural issues that should be reviewed and certified. We help the owner make decisions about various mounting systems (direct mount, ballast mount, fricion mount). We consider weight, strength, simplicity, and durability.
We review the dead loads of the solar panels and their mounting racks, then we look at the wind load on the roof structure based on height and location.
We check for loads that are are not distributed, but rather are concentrated on rails, mounting footings, roof structural members, or columns.
We look into anchoring methods and schemes, and best practice roof penetration sealing methods for anchors needed to resist uplift. We review supplier designs and drawings, or create design drawings for permit.
Finally, we provided on site inspections of the solar array installations in order to provided an engineer stamped inspection certification letter.
Solar Array Structural Consulting and Design
As we explain above, ECO provides structural design and inspection services for Solar arrays.
To help estimate performance, we can do a simple sun track chart review, or we can provide a full 3D sun study including trees and other shading items using Autodesk Revit.
For utility projects like the below 1/2 MW solar array, we can also help owners make faster 'what-if' economic decisions by performing a site solar layout. Then if it makes sense we can evaluate the potential with a cost analysis using solar advisor modeling software. Finally we can take the project into detailed design phase.
Small wind generators and solar photovoltaics can be combined into a single on-site green energy system to support a home's energy needs or to help charge a future plug-in electric vehicle overnight.
Residential Information for Greater Houston-Galveston Area Solar PV Array Installations
ECO is not a solar array provider or an installer. We provided design engineering to PV support installations. The means we can assist you or your selected solar provider company with system layouts and with structural detailing, and we can offer the following 'what is...' and 'how do I...' answers to get your own PV process started.
Orientation - Greater Houston’s Latitude Ranges from 29.7° to 30.1° North
Many 'Google search' guides suggest orienting for the Winter sun if a fixed position is used to optimize annually. But I suspect the text used in these guides was written in the first solar wave of the 70’s focused on northern climates and a need for solar thermal for hot water production. If you need that for Winter hot water production, Houston’s Winter Fixed Optimum is about 55.7 degrees off of horizontal. The same guides list Houston’s Summer Fixed Optimum as very nearly vertical, and Houston’s Spring and Autumn Fixed Optimums as 27.2 degrees off of horizontal.
To get more current results and outputs try one of many free online solar output calculators such as can be found at http://rredc.nrel.gov/solar/calculators/PVWATTS. These can show the optimum monthly and annual output in AC kW-hrs and in dollars per month. They cover both fixed orientation solar arrays and sun tracking arrays.
This online calculator indicates Houston's optimum angle to be at 25° off of horizontal.
However, Houston is also a high wind area so a lower orientation angle may prove to be better. A lower angle 'wind sail' the panels would be much more resistant to wind loads, and the output is not reduced by much, if compared to the 25° optimum angle
Orientation to 20° reduces output by ~0.5%
Orientation to 15° reduces output by ~1.5% (This is close to 3:12 roof pitch)
Orientation to 10° reduces output by ~3.0%
If you really want to recover that 0.5% to 3% loss and more, you can optimize your output by +/-20% by installing a system that allows you to manually adjust the orientation angles four times a year. To do this you would need to climb up and adjust your panel orientation on the first day of each of the four solar seasons:
Winter - Adjust on October 13 (to February 27)
Spring - Adjust on February 27 (to April 20)
Summer - Adjust on April 20 (to August 22)
Autumn - Adjust on August 22 (to October 13)
For a 4kW system, at $0.12/kwh this saves an extra $125 per year (or about $30 per climb!).
If you did not want to climb on your roof, you could do even better if you were to install an automatic full 2 axis solar tracking system. This will adjust the orientation angles in real time of every day to point directly at the sun. You could increase your output anywhere from 30% to 40% over fixed angle arrays. But the added cost is significant.
Additional Commercial Information for Texas Solar PV Array Installations
In addition to small and large residential projects, ECO has provided engineering for many commercial installations. Eco-Holdings Engineering has completed engineering for Commercial solar PV arrays of up to 145kW. As a result ECO has contacts with suppliers, installers, commercial roofers, and electrical contractors. ECO can coordinate information from all services to create a construction ready solar design.
These include several high schools, goverment, and private facilities like the Dallas Childrens Museum (below), and the Texas State Aquarium in CorpusiChristi. Retrofit projects require a detailed review of the as-built structures and the structural plans and details before the solar array's structural connection systems can be designed and certified. [Below photo courtesy of APS].
Is Solar a Money Maker?
We are now approaching a tipping point for price versus return. Right now assuming a reasonable $/kWh, if you finance a system as part of your 30 year mortgage, a new residential solar array can become a money maker.
If you want real numbers, ask your solar array provider needs to do a Present Value calculation with varying predictions for the cost of a kilowatt hour. You can start that calculation with current or predicted Solar array $/watt installed prices. This declining price predicting graph was recently published online by CNET)
Whether you think it is a money maker of not, progressive projects are being constructed with solar arrays, or designed for future solar arrays. (photos from ECO's structural support of a 7kW+ Meridian residential install)
Technical support of new energy opportunties
Installed in a CHP mode adjacent to a green building, a self-contained Capstone microturbine based charging station for electric vehicles could also augment the building's requirements for electricity, heat, and cooling.
These compact 70 and 200 kW power generation units would provide grid-independent charging to overcome grid overloading should plug-in electrics become widely popular.
Such stations could provide 480 volt charging without the need for expensive step-up transformers and would also be functional for recharging in remote locations.
Capstone’s products not only can supply electrical energy without further stressing the local utility grid, but in most cases around the world these CARB certified microturbine products are much cleaner than the local utility.
If added to a 24X7 off-electric-grid natural gas fueled microturbine based charging station, a solar PV array awning designed for 110+mph would provide customer shade while providing extra daylight charging power.