Hydro-Electric Evolution: Page 2 of 4

An Interview with Hydro Expert Chris Soler
Intermediate
Chris Soler purging the lines
Chris Soler purging the lines
Chris Soler prepares for a job digging a penstock ditch
Chris “The Human Backhoe” Soler prepares for a job digging a penstock ditch. Chris has spent many days and weeks of his life scoping out hydro sites; mapping out the best locations for intakes and turbines and the best routes for penstocks and transmission lines; and digging thousands of feet of ditches to protect and secure pipelines.
Early homebrew systems used car alternators
Chris’ early homebrew systems used car alternators matched with homemade or cast runners, with a square plastic bucket lid sandwiched between. The bucket (with tailrace channel or pipeline) was dug into the ground, and the manifold lines terminated in simple nozzles in the bucket’s sides. Snapping the lid on the bucket aligned the runner with the nozzles and set up the system for production.
One of Chris’ early homemade runners
One of Chris’ early homemade runners. As his understanding of hydro and his customers’ budgets increased, Chris switched to manufactured runners with much higher efficiencies, capturing more energy from the same head and flow.
A modern Harris hydro turbine
A modern Harris hydro turbine in one of Chris’ upgraded systems. The square bucket lid was supplanted by a manufactured housing and the used alternator replaced with a permanent-magnet alternator that was custom-designed for hydro systems.
Hydro intake screen
Chris learned early on that poorly designed and installed hydro intake screens can cause a lot of trouble, requiring frequent cleaning.
Self-cleaning screen
When self-cleaning screens became available, Chris found ways to use natural spots in the stream and a dab of concrete to set up durable, maintenance-free intakes.
Chris prepares low-pressure PVC pipe
Chris prepares low-pressure PVC pipe for the top end of a penstock.
High-density polyethylene pipe is heat-welded
High-density polyethylene pipe is heat-welded for a high-pressure portion of a penstock.
Battery Bank
As Chris’ customers’ energy needs became larger, the systems grew and improved. Upgrading from early 12 VDC systems to standard 48 VDC battery/inverter systems increased efficiency and energy possibilities.
Modern solar controllers in smaller and simpler configuration
Modern solar controllers—with some protection and electronic wizardry—have allowed significantly better production from hydro systems. They can sometimes be used in smaller and simpler configurations.
Modern solar controllers in larger, multiple-inverter systems
Modern solar controllers—with some protection and electronic wizardry—have allowed significantly better production from hydro systems. They can also be used in larger, multiple-inverter systems with higher production and loads.
Using manufactured components
Upgrades like this one use manufactured components, while still keeping the budget low.
Underside of the turbine
The underside of the turbine is exposed as Chris inspects the runner and nozzles. The turbine bolts on a bucket that is cemented into the ground. Note the large tailrace pipe that returns the tailwater to the stream.
Chris Soler and Don Harris
Chris, along with many other hydro contractors and users, owes a large debt to retired hydro pioneer Don Harris, who helped a whole generation of people with his excellent equipment and generous technical support.
Chris Soler purging the lines
Chris Soler prepares for a job digging a penstock ditch
Early homebrew systems used car alternators
One of Chris’ early homemade runners
A modern Harris hydro turbine
Hydro intake screen
Self-cleaning screen
Chris prepares low-pressure PVC pipe
High-density polyethylene pipe is heat-welded
Battery Bank
Modern solar controllers in smaller and simpler configuration
Modern solar controllers in larger, multiple-inverter systems
Using manufactured components
Underside of the turbine
Chris Soler and Don Harris

How has the industry and technology changed in the decades since you started? What are the biggest advances in technology?

The microhydro business is still a small, niche market. Most products, with the exception of the turbines themselves, are adapted from the solar market. The North American turbines are from microhydro pioneers such as Don Harris of Harris Hydro; Paul Cunningham of Energy Systems & Design (ESD); and Jerry Ostermeier of Alternative Power & Machine (APM). It has been nice to be able to call up and talk directly with the people who designed and built the units. When Don Harris retired, I was worried about being able to get parts and new turbines. However, Denis Ledbetter has taken over the production of the turbines and repair parts.

In 2001, Don Harris started producing his adjustable permanent-magnet generators for his hydro turbines. I switched to those and got a 40% jump in power output. I then realized that further improvements were coming from specialized manufacturers.

Today’s typical systems are much larger, and the owners are more concerned with reliability and ease of use than back in my homebrew days. Using permanent magnets eliminates the changing of brushes in alternators. Using self-cleaning intake screens (like the Coanda-type) cuts down on the time required to clean intakes. High voltage/low current (which requires smaller, and therefore less expensive, wire) is now possible with maximum power point tracking (MPPT) adapted from solar-electric systems. Specialized breakers handle the higher voltages. Sine-wave inverters run all of the AC loads without the worry of damaging sensitive electronics, which sometimes occurred with older, modified-square-wave inverters.

Walk us through a typical upgrade of one of your early hydro systems. What does an upgrade like this change, and what is the performance improvement?

Some of my older systems are still 12 V and producing modest amounts of power. Other systems have gradually added more solar-electric modules to the renewable energy mix. The hydro resource is usually limited, so higher efficiency is the only way to get more power. I look at what the owner wants to accomplish and see what improvements are possible.

Many of my hydro systems I upgraded as new products became available, and as more power or better reliability was needed. All the systems are now using permanent-magnet alternators. By continuing to use the original Pelton wheels, Don Harris was able to keep the upgrade costs low.

Some of my clients switch to higher voltage with MPPT controllers to minimize the line losses associated with increased output current. Some systems extend the pipeline to increase the head, if available. The switch to self-cleaning screens cut losses caused by plugged intakes. Upgrading to a larger-diameter penstock to cut friction loss can allow more water flow.

Tell us more about MPPT for hydro.

The introduction of reasonably priced MPPT controllers for solar has opened up new design possibilities for small DC hydro systems. Before MPPT controllers were available, the hydro generator had to run at the battery voltage. That meant large wires, or accepting large voltage loss in the long-distance wires.

Now with the DC-to-DC conversions in the MPPT controllers, it is possible to operate the hydro at high voltage to keep the amperage low, minimizing line losses on long-distance wires. The MPPT units also allow the hydro turbine to run at the speed and voltage that produces the most power. Some small hydros allow varying the strength of the magnets to better match the varied flow of a stream, but the MPPT will unload the unit to let it speed up, and do the adjusting automatically.

Comments (3)

jhd's picture

hi - i am very new to hydro power. me and my husband have bought a site with an old mill ruin - two leads and a weir. we want to develop the mill site into a small self sufficient house. it makes sense to use the power we already have in the stream. i can't seem to find turbines small enough to fit in the lead though. We have very little budget and are based in the uk..any hints on where to start? many thanks jo

Ian Woofenden's picture

Hi jo,

Hugh Piggott in Scoraig Scotland does a fair amount of hydro, and may be able to help you or refer you to someone closer. You'll easily find his contact info online by searching his name and location.

Regards,

Ian Woofenden
Home Power senior editor

Andrew Romaniuk's picture

very good

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