Photo: a vortex before the turbine is connected
A frequent contributor to this blog, the author proposes a compelling solution to power problems in a small and mountainous, beautiful but poor Himalayan Kingdom with streams and rivers in abundance. The solution isn't what you might think....
By David DuByne
Nepal faces a load-shedding crisis: each year at certain times, electrical authorities cut off electric current on certain lines when power demand becomes greater than supply. As Ratna Sansar Shrestha explains in Hydro Nepal magazine, large-scale hydro projects can’t keep up with 10.7% annual increases in power demand. This is because of Nepal Electricity Authority’s (NEA) delayed completion of projects, system mismatches in the seasonal variation of water and inadequacies in much of this mountainous country’s infrastructure. As a result, severe load-shedding will continue at least into the dry season of 2017.
Economic losses from these planned interruptions include liquid fuel shortages as households and businesses burn fuel in generators that was destined for the transportation sector.
These are the problems. Where are the solutions? Perhaps the best way to answer the question is to pose another one: If large-scale doesn’t work, what about small-scale?”
I have worked with renewable energy concepts over the last several years, and I think Gravitational Vortex Power (GVP) is a solution that could work for Nepal. Let me explain how it works.
You will notice when you pull the plug from a sink that when the water gets low it starts to spin into the drain hole. It actually makes a mini-whirlpool as the last of the water drains out. Scale that round hole up from something that is 12 cm in diameter to something with a 5-meter diameter and you create a larger amount of spinning water with a larger amount of kinetic energy. Gravity does all the work as water flows. Now add curved blades to dig into the spinning water, attach an electrical power generator and you have GVP. The rotational movement of water in the shallow circular basin creates a stable continuous gravitational vortex, 24 hours per day, seven days a week.
Viktor Schauberger from Austria was one of the first to make use of vortex dynamics from 1929-1936, and his has work influenced others. Zotloterer’s current design needs a 0.8 meter water drop and two cubic meters per second of water flow. That doesn’t sound like a lot of water to produce power, but these GVP plants produce 57,000 kWh per year. For comparison, per capita usage of electricity in Nepal was 78.5 kWh per year in 2010.
How can GVP be a Solution?
Kathmandu faces its own set of challenges, while in the countryside another set of variables limits the availability and supply of power. So how does using small hydro affect change in the national power grid? It boils down to economics and scale of raw material input for targeted output.
Let’s look a single Large Scale Project first, the Upper Tamakoshi Hydroelectric Project. The project, which will have a maximum output of 456 MW per day during the monsoon, will cost an estimated US$441 million, excluding interest. Maximum output will drop by 60% or more during the dry season.
Additional costs will include 132 kV high voltage transmission lines for future grid extension: between $8000–10,000 per kilometre, rising to $22,000 in difficult terrain. Then there is the cost of sub-station construction and additional road building at $20,000 per km. So assuming that everything is on budget (unlikely, based on past performance), let’s round off to $500 million. And one more thing: most of the new lines will by-pass rural communities in Nepal as they wend their way to India to serve Power Purchase Agreements (PPA’s).
By comparison, small GVP plants can use local materials, can cost as little as $10,000 and do not need to dam the water to operate. The GVP plant merely uses the water for a few seconds as it flows on its way down stream. Just the environmental advantages to its usage warrant further investigation as a solution. GVP is designed to be installed in remote areas that would never see grid expansion into local villages and is designed to electrify a small community of up to 200 homes per plant under Nepali consumption patterns.
If we use the same figure of $500 million for one large project that provides diminishing electrical output as rains decrease from October to May each year, you could build 50,000 GVP plants. These plants generating 57 MWh per year would equal 2,850,000MWh or 2,850 GWh annually fed directly to the local communities in remote locations that need it most. Here is where the shocking part comes in: the forecast annual energy output from the Upper Tamakoshi Project is 2,281 GWh. You generate more power from GVP, save on the amount of construction materials and do not need to dam an entire river!
With Nepal’s special set of circumstances we must think in inverse terms. The usual train of thought is to electrify from major population centers out to the countryside, but in Nepal’s case it needs to be the opposite to reduce load-shedding. This country needs to electrify from the countryside back into the cities, as most cottage industries are located outside large urban areas. The economy is stagnating from lack of power in these areas. If rural communities can generate their own power locally off the main grid, then excess power not consumed in smaller outlying districts can be diverted back into Kathmandu or other cities languishing in the dark.
Another benefit beyond revitalization of the rural economy would be that materials used for local construction will be bought locally and those living close to the GVP plants can maintain and repair the generators themselves, not relying on German engineers being flown in to Nepal to work on a damaged large-scale generator. Under this system electrical lines are local, minimizing their cost. The can be bought from local vendors and strung up on already existing electrical poles. This means revenue circulates throughout a local area and the community sees a direct economic benefit.
These ideas sprang to mind while I was walking home and saw a sign that proudly stated “load-shedding solutions.” The solutions in this little store included batteries, inverters and so on.
No way. GVP is the solution to Nepal’s load-shedding crisis. My hope is that a Rotary Club or some other humanitarian organization will work with us to help lead the way.
David DuByne is Advisor and Director of Foreign Co-operation with Energy Research Nepal. He can be contacted at David.DuByne@ERN.org.np