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Designing for simplicity, efficiency and reliability: An interview with SPG Solar Director of Commercial and Utility Products Bill Elwell

Bill Elwell
Bill Elwell

With over 10 years of industry experience, Bill Elwell leads the Commercial & Utility Products division at SPG Solar which includes two proprietary products: SPG Solar Sunseeker single-axis tracker and SPG Solar Floatovoltaics. Bill works with the design, engineering, operations and supply chain teams at SPG Solar to ensure products meet industry standards and client needs.


With his over 3 years at SPG Solar where he made significant contributions to business development and design & engineering, and his previous experience in the civil engineering, land surveying and development fields, Bill is positioning SPG Solar as a solar product innovator.



Solar Server: Tell me a little bit about your tracker system. In a market with so many tracker designs, what differentiates it from other systems?

Bill Elwell: SPG Solar is a leading producer of single-axis trackers. We have approximately 40 MW of installed trackers throughout the United States. A key differentiator of our tracker is installation time. The installation time of our tracker is very similar to what it is with a fixed-tilt system. A key driver of this is that the posts per MW of our tracker are much lower, sometimes as low as 30%, 40% lower than other single-axis trackers available on the market. The reason for that is that we mount three modules in landscape, with large north-south spans.

You can mount three modules at a time at the site, or in a controlled environment off-site, and then rapidly install three at a time. So that really reduces your labor cost, your wiring cost and your installation time, which all helps with the overall levelized cost of the project.

Also, every motor can power up to 620 kW of solar. That means on a 1.25 MW DC system, two individual motors are required to move the entire system. This helps reduce operations and maintenance costs by  reducing the point of failures that could potentially happen on a system; it makes for a very simple solar system that lasts for 25 years or more.


Solar Server: This strikes me as a very different design, to have these big wings and multiple modules mounted on only a few motors. Do you see other tracker companies emulating this design?

Bill Elwell: There are a few others that are doing something similar. What you see on a lot of those is a motor, but then they will also have an actuator on the rows, and on the columns. But because of our 20-ton screw that drives a ram shaft, we don't need the actuators. There is enough force in that motor, and the screw, and enough robustness in the design to eliminate the need for any actuator on any individual rows.


Solar Server: So why aren't other companies following this design?

Bill Elwell: I don't know the answer to that, but I think a lot of them have gone the hydraulic route, maybe they don't have such a robust design, so they need a little more support and a little more power at each individual row. This is something we came up with, we have full wind-tunnel results that show it is well engineered and fully capable of withstanding the elements.


Solar Server: To take a step back, tell me a little about SPG Solar as a company and your services.

Bill Elwell: SPG Solar has been around since 2001. We are a leading solar energy provider  with roughly 70 megawatts installed nationwide. We are a one stop shop, offering not only full EPC work for commercial systems, but we also offer structured finance; a full design and engineering team; a product division which has the single-axis tracker and a floating solar power system – SPG Solar Floatovoltaics; a full operations & maintenance team, which does operations, maintenance, and preventative maintenance, both for SPG Solar and for other companies in the industry.

SPG Solar simply builds the highest performing, most reliable solar power systems for clients ranging from large commercial, industrial, government and public energy users.


Solar Server: There are plenty of large PV projects that are using trackers. There are also plenty of large ground-mounted projects that aren't. Can you talk about how you sell a tracking system and the choices that a company makes?

Bill Elwell: One of my primary objectives is to educate the solar industry who is not familiar with trackers, who would normally go with a fixed-tilt system, to realize that a tracker makes financial sense and increases production by up to 20%.

3 MW-DC PV plant with SPG Sunseeker tracking system on a brownfield in Sacramento, California. Image source: SPG Solar Inc.
3 MW-DC PV plant with SPG Sunseeker tracking system on a brownfield in Sacramento, California. Image source: SPG Solar Inc.

It is important to know what the real O&M time-frames are, what the real costs are, and to get people comfortable with using a tracking system. As long as you find the right partner who ensures installation is done properly, on time and the system is maintained, the tracker is a very simple, efficient and reliable design.


Solar Server: Now you mentioned that your markets are primarily in the U.S. West right now. What do you see for the future of SPG Solar in terms of markets? Where are your next places to expand, or are you trying to consolidate those markets?

Bill Elwell: We want to expand on what we are good at; we continue to focus on the Western, Southwestern, and the Southeastern regions in the United States, because those markets have some of the best solar resources available. The farther South you go in latitude the more production you get out of a single-axis tracker.

But that doesn't mean that a market can't pop up that could have good incentives, and that can offer increased subsidies for more kWH production. Anywhere in the U.S. could offer that, and our single-axis tracker would be compatible.

We also see a lot of opportunity outside of the United States, both in Central America, Puerto Rico, Dominican Republic, places where the cost of electricity is extremely high-- they are shipping in oil; they are paying USD $0.25 to $0.30 per kilowatt-hour..You can install a single-axis tracker which can provide extremely high production in those areas for a far lower price.

1 MW-DC PV plant with SPG Sunseeker tracking system at Mammoth Community Water District in Mammoth Lakes, California. Image source: SPG Solar Inc.
1 MW-DC PV plant with SPG Sunseeker tracking system at Mammoth Community Water District in Mammoth Lakes, California. Image source: SPG Solar Inc.

Solar Server: Are you seeing a lot of movement in Latin American markets? I know that these markets have been a bit slow to pick up. What are your thoughts on the future?

Bill Elwell: I think the markets will pick up, and it is based on the cost, it's based on the subsidies that the governments are putting in place. It's a mind-set as well, if they feel like renewable energy is the right thing to do, it's probably going to happen.

In the last six months we've seen a much greater demand for projects in those areas.


Solar Server: Specifically in which nations are you seeing this increased demand?

Bill Elwell: Well, like I said earlier, the Dominican Republic, Puerto Rico, places like that. But I would imagine that would expand to many others.


Solar Server: Given that the tracker market has some large, very well-established players like DEGERenergie, what are your strategies for competing with these larger players and for building market share for SPG Solar?

Bill Elwell: Our main strategy is to be an extremely reliable company. We want to make promises, and we want to deliver on those promises. So if we say we are going to give you 10MW a month for the next year, we want to do that.

We also want to make sure that our product is the best in the industry. We aren't going to reduce our cost so much that the product no longer holds up to its warranty. It's extremely important for any solar system to be operating at 100%, as much as possible to maximize your return on investment for the solar system.


Interview conducted by Christian Roselund