This is the final installment of a series examining the V.I. Water and Power Authority’s net-metering program, its challenges, and its future. For previous installments see Related Links below.
If net metering has proven so successful and popular, why wouldn’t the legislature and the Water and Power Authority work to raise the 15MW maximum production cap to keep the program around? It’s a simple question with a complicated answer, and one that has little to do with policy.
In the next few years, the U.S. Virgin Islands will have to contend with an engineering problem that has bedeviled the renewable energy industry around the globe – there is a physical limit to the amount of energy from solar arrays and wind turbines that energy grids can handle before becoming unstable.
All sources of energy can be separated into two major categories: dispatchable energy and intermittent energy. Dispatchable energy provides the bulk of the electricity on utility grids, often referred to as the base load.
Electrical engineers like dispatchable energy because it’s easy to control. This category includes any type of energy from a power plant in which the input of fuel can be adjusted to increase or decrease the output of electricity.
Nuclear plants as well as those that burn fossil fuel, such as diesel or coal, are dispatchable power providers. There are some renewable sources of dispatchable energy as well, such as biomass and trash-to-energy plants.
Intermitment energy providers are those in which the input of fuel and output of electricity are out of the hands of engineers. Wind and solar are the two most common examples. No one can force the wind to blow or the sun to shine. As a result, the energy output from these sources is sporadic and difficult to predict.
Melton Smith, design and construction manager for WAPA, said that for utilities to ensure that the lights don’t go out, they must find a balance between the amount of electricity they know will be available at any given point and the electricity that might be there.
“If we have sufficient renewable energy systems out there that we can turn off a generator, that’s a good thing on one side and a bad thing on the other side,” he said.
He explained that on a sunny day, solar panels could provide enough energy to allow WAPA to idle some of its generators, thereby saving money on fuel costs. But what happens if a cloud goes by? Smith says WAPA would have to scramble to get its generators restarted to compensate for the sudden dip in energy production.
If that dip is too large, he said, it could cause blackouts while generators at the power plant are coming back online.
In order to integrate solar and wind into their energy mix, utilities must conduct studies to determine how much intermittent energy their grid can sustain before they begin risking service interruptions.
Clinton Hedrington, director of transmission and distribution for WAPA, said they’ve conducted two such studies on the Virgin Islands’ grids. The first suggested they could tolerate a 10-percent penetration rate from intermittent sources. The second estimated 20 percent. Exactly where the threshold lies will take experimentation and very careful planning.
So just how far away are we from hitting our intermittent energy limit? It’s closer than you might think.
Since there is no electrical interconnection between the St. Croix and St. Thomas/St. John districts, the total Virgin Islands electrical grid, which would be tiny by stateside standards to begin with, is divided into two even smaller grids, so the amount of intermittent power needed to hit the 10- to 20-percent mark on either isn’t much.
Hedrington said he believed the territory could handle the 15MW of intermittent energy allotted to the net-metering program as well as the 18MW that will come from industrial solar arrays slated to come on line next year. Anything beyond that, he said, will raise complications.
“If you have so much penetration by solar, and then you add wind, you become much more unstable. And that’s a big deal,” he said, referencing a proposed industrial wind farm at the Bovoni landfill on St. Thomas. “You know, we’re doing all of this wind study and then we’re also at max with solar, that’s going to cause a problem, and we know that.”
Hedrington said a possible solution is to install industrial-sized batteries throughout the grid to help even out the flow of electricity from intermittent sources, though exactly how this would be implemented has not yet been planned.
The Virgin Islands government is negotiating with the Clean Energy Coalition, a stateside nonprofit group, to launch a pilot program on St. John that will attempt to raise the penetration barrier through the use of batteries. The study could start next year and, if successful, could establish a roadmap for the rest of the territory to follow suit.
Hedrington said another possible solution would be to connect the territory to Puerto Rico’s grid. As part of a much larger grid, the amount of renewables the territory could install would skyrocket.
“The interconnection to Puerto Rico raises our penetration to infinity,” Hedrington said. “We could add renewables, add renewables, add renewables and just rely on them to deal with the intermittency.”
The interconnection to Puerto Rico is still just a proposal, however, and there are presently no plans to build it.
So what does this mean for the net-metering program? In all likelihood, when the 15MW production cap is reached sometime in the next two to four years, the program won’t be extended. Those in the program will continue to enjoy the benefits of net metering, but new customers will not be added.
Hedrington made it clear that as the territory begins to flirt with its intermittent penetration limit, every new proposed megawatt of solar and wind energy will require extensive planning and potentially infrastructure improvements. With a large solar farm on the way and several proposed industrial wind projects on the drawing board, there may not be any room left for small-scale net-metering installations beyond the 15MW cap.
“While we don’t want to be against the penetration of renewables, we have to protect the grid. Because it will be detrimental at the end of the day,” Hedrington said.
You have no idea what you are doing. Leave it alone. Green energy here will raise the cost of energy enormously like it has everywhere else. That is not what we need here right now. We don’t need the higher cost of anything. And we don’t need the government screwing it all up which is what they will do. Not to mention . . . how beautiful will all those windmills look? UGLY. And how beautiful will all those solar panels look? UGLY. This is a bad idea put forth by people who think in the stone age.
I’ve got to say that the idea which you (cgtstx) have is “Stone Age” thinking. How in this modern World can folks living in an 800 square foot house, pay a WAPA bill of over $400.00- $500.00 per month, just for electrical portion of it, unacceptable is what I say to that. You say ” leave it alone” here is another question to you, what era are you living in? Look, I don’t mean to demean you and your thoughts, it’s totally fine if you don’t find anything wrong with the WAPA bill which you receive, but there lots of folks finding it hard to pay these astronomical bills on a monthly bases, to a company who actually has outdated diesel run turbines to power our homes and businesses, businesses which are shutting down or will be closed because of WAPA Stone Age thinking and methods.
To answer your “windmill” comment, it’s a Wind Turbine which produce electricity through kinetic energy ( wind power) . I’m a Wind Turbine technician, and producing power from wind, in an offshore environment will do wonders for our territory as long long as the studies are done properly. To the looks of these turbine, it’s an individuals opinion on that.
The bottom line is that the V.I. grid needs to be updated to the smart grid system, in order to make any changes into this new modern world. It’s full time that we demand that the V.I. Government get out of the old age, they are still ten years behind in EVERYTHING!
You are correct about the government screwing things up, because we have elected idiots to run our territory, we need to revamp the whole political system, point blank. One last thing, Green energy lowered energy cost and promoted local jobs in so many areas, but that’s my research and experience, something we all need and can use.
Stand firm.
I never said that I find the WAPA bills acceptable. They’re crazy. And the idea of green energy here is double crazy and will ruin the vistas and increase its cost – by a lot. THAT is reality. Wind Turbines are mess in most places they’ve been tried. They break down. Are noisy. And have a negative impact on birds and wildlife. THAT is reality. Green energy is pie in the sky. What they should be doing is trying to find a way power the VI with natural gas. Cheap and reliable. No one is saying that WAPA is acceptable. They’ve never been acceptable or competent. But the promise of “Green Energy” is not a cheaper alternative nor is it way to keep our islands beautiful.
We agree on many things, and have disagreed on some, that’s life, we’re human, we make mistakes as citizens. Wind turbines can be place offshore, typically ten miles from the shoreline in most cases, depending on the KW. It will be out of sight for the most part. Proper studies need to be made for them to be placed out of migratory birds flight paths, and placed strategically in constant wind flow in order to reap the benefits. Turbines are mechanical and will need repairs, of course, but if one goes down, one will be repaired, unlike the old generator(s) WAPA has, when it goes down, you know half the island is out of power, lol.
Look here, natural gas is cheap for the areas which produce it, just remember it has to be shipped in like everything else we depend on in the territory. We do have Caribbean islands producing natural gas, like Trinidad, one the largest producers, but the problem is that it has to be shipped in. With the idea of natural gas being an alternative, WAPA has to convert their system and upgrade or most likely rebuild a new power plant to accommodate natural gas. Either way, whether solar, wind or natural gas, we the people will have to pay a hefty sum of money to them, though its not our fault, we are stuck with the tab.
By the way, I like your comments and if there were more people voicing their opinions of the matter, or any matter of concern, we would be headed in a much better way of life for our territory, one love.
Stand firm.