Category Archives: Power Grid

How Do Solar Cells Work?

Power Grid, Solar Energy, , , , , ,
In the last two decades, the contribution of solar energy to the world’s total energy supply has grown significantly. This video will show how a solar cell or photovoltaic cell produces electricity. Energy from the Sun is the most abundant and absolutely freely available energy on planet earth.

In order to utilize this energy, we need help from the second most abundant element on earth sand. The sand has to be converted to 99.999 % pure silicon crystals, to use in solar cells. To achieve this, the sand has to go through a complex purification process as shown.

The raw silicon gets converted into a gaseous silicon compound form. This is then mixed with hydrogen to get highly purified Polycrystalline silicon. These silicon ingots are reshaped and converted into very thin slices called silicon wafers.

The silicon wafer is the heart of a photovoltaic cell. When we analyze the structure of the silicon atoms, you can see they are bonded together. When you are bonded with someone, you lose your freedom.

Similarly, the electrons in the silicon structure also have no freedom of movement. To make the study easier, let’s consider a 2d structure of the silicon crystals. Assume that phosphorus atoms with five valence electrons are injected into it.

Here, one electron is free to move. In this structure. When the electrons get sufficient energy, they will move freely. Let’s try to make a highly simplified solar cell only using this type of material.

When light strikes them, the electrons will gain photon energy and will be free to move.. However, this movement of the electrons is random. It does not result in any current through the load. To make the electron flow unidirectional, a driving force is needed. An easy and practical way to produce the driving force is a PN junction. Let’s see how a PN Junction produces the driving force. Similar to n-type doping, if you inject boron with three valence electrons into pure silicon, there will be one hole for each atom.

This is called p-type doping. If these two kinds of doped materials join together, some electrons from the N side will migrate to the P region and fill the holes available. There. This way, a depletion region is formed where there are no free, electrons and holes.

Due to the electron migration, the N-side boundary becomes slightly positively charged. And the P side becomes negatively charged. An electric field will definitely be formed between these charges.

This electric field produces the necessary driving force. Let’s see it in detail. When the light strikes the PN Junction, something very interesting happens. Light strikes the N region of the PV cell and it penetrates and reaches up to the depletion region. This photon energy is sufficient to generate electron hole pairs in the depletion region. The electric field in the depletion region drives the electrons and holes out of the depletion region.

Here we observe that the concentration of electrons in the N region and holes in the P region become so high that a potential difference will develop between them. As soon as we connect any load between these regions, electrons will start flowing through the load.

The electrons will recombine with the holes in the P region after completing their path.. In this way, a solar cell continuously gives direct current. In a practical solar cell you can see that the top N layer is very thin and heavily doped, whereas the P layer is thick and lightly doped. This is to increase the performance of the cell. Just observe the depletion region formation here. You should note that the thickness of the depletion region is much higher here compared to the previous case.

This means that, due to the light striking the electron hole, pairs are generated in a wider area compared to the previous case. This results in more current generation by the PV cell. The other advantage is that, due to the thin top layer, more light energy can reach the depletion region.

Now, let’s analyze the structure of a solar panel. You can see the solar panel has different layers. One of them is a layer of cells. You will be amazed to see how these PV cells are interconnected. After passing, through the fingers, the electrons get collected in busbars. The top negative side of this cell is connected to the back side of the next cell through copper strips. Here it forms a series connection.

When you connect these series connected cells, parallel to another cell series, you get the solar panel. A single PV cell produces only around 0.5 voltage. The combination of series and parallel connection of the cells increases the current and voltage values to a usable range.

The layer of EVA sheeting on both sides of the cells is to protect them from shocks, vibrations, humidity and dirt. Why are there two different kinds of appearances for the solar panels? This is because of the difference in the internal crystalline lattice structure.

In polycrystalline solar panels, multi crystals are randomly oriented. If the chemical process of silicon crystals is taken one step further, the polycrystalline cells will become monocrystalline cells.

Even though the principles of operation of both are the same. Monocrystalline cells offer higher electrical conductivity. However, monocrystalline cells are costlier and thus not widely used. Even though running costs of PV cells are negligible.

The total global energy contribution of solar voltaic is only 1.3 percent. This is mainly because of the capital costs and the efficiency constraints of solar voltaic panels which do not match conventional energy.

Options. Solar panels on the roofs of homes have the option to store electricity with the help of batteries and solar charge controllers. However, in the case of a solar power plant, the massive amount of storage required is not possible.

So generally, they are connected to the electrical grid system in the same way that other conventional power plant outputs are connected. With the help of power. Inverters DC is converted to AC and fed to the grid.

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Source : Youtube

Tesla Powerwall Review – Angela’s Story

Clean Energy, Energy Storage, Power Grid, Solar Energy, Solar Equipment,
A lot of people wonder whether buying a Tesla Powerwall, is a good investment. Well, we recently spoke to Angela, one of our recent customers about what she’s getting from her Tesla Powerwall. So when the installation happened and part of that sort of sign over process was like, Okay, now we’re gonna show you what it would be like, in a blackout and obviously, nothing happened for me.

It was an experience because my fridge kept being on, I think that was all that was running at the time. But you know, that’s probably the most important thing. For me, is probably only the kettle cause I love a cup of tea.

My computer – I could probably do without it because you know, as long as I can charge my phone, I can run my business. But my children would probably argue that they would need every powerpoint for their … To charge their devices. But for me the kettle is the most important thing we moved from a very small property, like 90 square meters to now sort of a two story house with a pool. So I thought oh my gosh, like, we’re gonna use power a lot more.

I could see it only being an advantage. And in the end, it has been. No one actually said to me, you’re going to get 99%, and I think on a yearly average I’m I think I’m at 96% self sufficient every day.

But that’s because there are some days in winter where you know, you might have rainy days, so that brings the average a little bit down, but really in the last two or three months, I’ve been 99% every day.

I was at $600 per quarter. And my last bill, which was the first bill with a fully installed Powerwall was minus, I think minus $45 But that was sort of running at the end of spring. So now summer I can see I have contributed a significant amount more of energy or kilowatts.

Back to the grid, so I’m expecting a little bit more. And, I actually put that towards my gas bill. This is no surprise to anyone we mean we’re putting a big pressure on Mother Earth. And I really feel you have to start with yourself.

So if I can do this in my own household, then other people could do it too. Yes, I’m also contributing back energy into the grid on a small scale, but still I’m doing something and I think if anyone, if anyone could do the same, then together we can really make a difference.

Source : Youtube

Electrical Engineer Warns Power Grid At Risk From Severe Solar Storm

Power Grid,

An electrical engineer who specializes on the power grid is warning that the grid is at risk of failure should a large scale solar storm occur.

Power grid failure – both short term and long term – is one of the more popular reasons why consumers choose to install a solar pv system at their residence.

Honolulu Civil Beat reports:

On Sept. 1 and 2, 1859, telegraph systems around the world failed catastrophically. The operators of the telegraphs reported receiving electrical shocks, telegraph paper catching fire, and being able to operate equipment with batteries disconnected. During the evenings, the aurora borealis, more commonly known as the northern lights, could be seen as far south as Colombia. Typically, these lights are only visible at higher latitudes, in northern Canada, Scandinavia and Siberia.

What the world experienced that day, now known as the Carrington Event, was a massive geomagnetic storm. These storms occur when a large bubble of superheated gas called plasma is ejected from the surface of the sun and hits the Earth. This bubble is known as a coronal mass ejection.

The plasma of a coronal mass ejection consists of a cloud of protons and electrons, which are electrically charged particles. When these particles reach the Earth, they interact with the magnetic field that surrounds the planet. This interaction causes the magnetic field to distort and weaken, which in turn leads to the strange behavior of the aurora borealis and other natural phenomena. As an electrical engineer who specializes in the power grid, I study how geomagnetic storms also threaten to cause power and internet outages and how to protect against that.

https://www.civilbeat.org/2022/12/a-large-solar-storm-could-knock-out-the-power-grid-and-the-internet-an-electrical-engineer-explains-how/

You can read the entire article at civilbeat.com.

How do solar panels work?

Power Grid, Solar Energy, Solar Equipment, ,

The Earth intercepts a lot of solar power: 173 thousand terawatts. That’s ten thousand times more power than the planet’s population uses. So is it possible that one day the world could be completely reliant on solar energy? To answer that question, we first need to examine how solar panels convert solar energy to electrical energy.

Solar panels are made up of smaller units called solar cells. The most common solar cells are made from silicon, a semiconductor that is the second most abundant element on Earth. In a solar cell, crystalline silicon is sandwiched between conductive layers.

Each silicon atom is connected to its neighbors by four strong bonds, which keep the electrons in place so no current can flow. Here’s the key: a silicon solar cell uses two different layers of silicon.

An n-type silicon has extra electrons, and p-type silicon has extra spaces for electrons, called holes. Where the two types of silicon meet, electrons can wander across the p/n junction, leaving a positive charge on one side and creating negative charge on the other.

You can think of light as the flow of tiny particles called photons, shooting out from the Sun. When one of these photons strikes the silicon cell with enough energy, it can knock an electron from its bond, leaving a hole.

The negatively charged electron and location of the positively charged hole are now free to move around. But because of the electric field at the p/n junction, they’ll only go one way. The electron is drawn to the n-side, while the hole is drawn to the p-side.

The mobile electrons are collected by thin metal fingers at the top of the cell. From there, they flow through an external circuit, doing electrical work, like powering a lightbulb, before returning through the conductive aluminum sheet on the back.

Each silicon cell only puts out half a volt, but you can string them together in modules to get more power. Twelve photovoltaic cells are enough to charge a cellphone, while it takes many modules to power an entire house.

Electrons are the only moving parts in a solar cell, and they all go back where they came from. There’s nothing to get worn out or used up, so solar cells can last for decades. So what’s stopping us from being completely reliant on solar power? There are political factors at play, not to mention businesses that lobby to maintain the status quo.

But for now, let’s focus on the physical and logistical challenges, and the most obvious of those is that solar energy is unevenly distributed across the planet. Some areas are sunnier than others. It’s also inconsistent.

Less solar energy is available on cloudy days or at night. So a total reliance would require efficient ways to get electricity from sunny spots to cloudy ones, and effective storage of energy. The efficiency of the cell itself is a challenge, too.

If sunlight is reflected instead of absorbed, or if dislodged electrons fall back into a hole before going through the circuit, that photon’s energy is lost. The most efficient solar cell yet still only converts 46% of the available sunlight to electricity, and most commercial systems are currently 15-20% efficient.

In spite of these limitations, it actually would be possible to power the entire world with today’s solar technology. We’d need the funding to build the infrastructure and a good deal of space. Estimates range from tens to hundreds of thousands of square miles, which seems like a lot, but the Sahara Desert alone is over 3 million square miles in area.

Meanwhile, solar cells are getting better, cheaper, and are competing with electricity from the grid. And innovations, like floating solar farms, may change the landscape entirely. Thought experiments aside, there’s the fact that over a billion people don’t have access to a reliable electric grid, especially in developing countries, many of which are sunny.

So in places like that, solar energy is already much cheaper and safer than available alternatives, like kerosene. For say, Finland or Seattle, though, effective solar energy may still be a little way off. Solar panels in Maine, however, are a wise investment.

Source : Youtube

4 Power Substations Vandalized Over Christmas Weekend

Power Grid

In what is becoming a very alarming trend, 4 power substations were vandalized in Washington State over the Christmas weekend. The act of violence resulted in 14,000 customers losing their power on Christmas Day.

As if soaring electricity rates, rolling blackouts and forecasted supply shortages of solar equipment weren’t reason enough to consider adding a solar energy system to your home in Maine, you can add deliberate acts of violence to the list.

There are currently no arrests, nor even any suspects.

ABC News reports:

“The search continued Monday for vandals who targeted four power substations on Christmas Day in Pierce County, Washington, setting fire to at least one of the facilities and knocking out power to more than 14,000 utility customers, authorities said.

Two of the break-ins were at Tacoma Public Utilities substations and two others were at a Puget Sound Energy station, according to the sheriff’s office in Pierce County, which encompasses Tacoma.

No arrests have been announced.

The vandalism came amid a string of similar sabotage incidents across the country, including several in the Northwest, and follows a bulletin issued last month by the U.S. Department of Homeland Security warning that critical infrastructure could be among the targets of possible attacks by “lone offenders and small groups motivated by a range of ideological beliefs and/or personal grievances.”

“It is unknown if there are any motives or if this was a coordinated attack on the power systems,” the Pierce County Sheriff’s Office said in a statement.

The substation attacks unfolded Sunday between 2:39 a.m. and 7:21 p.m. local time, authorities said. In all four episodes, the saboteurs broke into the fenced-off power stations and deliberately damaged equipment, according to the sheriff’s office.

Officials initially said three power stations were vandalized, but early Monday morning they said a fourth substation was damaged in a deliberately caused fire near the city of Graham, cutting power to homes in Kapowsin and Graham.”

https://abcnews.go.com/US/2-power-substations-attacked-washington-state-7k-lost/story?id=95812232&cid=social_twitter_abcn

You can read the full story at ABC News.

Historic Winter Storm The Cause of Rolling Blackouts Over Christmas Weekend

Power Grid

An historic winter storm that delivered blizzard conditions and record cold across much of the U.S. over Christmas weekend was credited with causing rolling blackouts over several states during the Holiday weekend.

Rolling blackouts that lasted anywhere from 15 minutes to a few hours were seen in several states including Tennessee, Kentucky, Alabama, Mississippi, and Georgia.

The power grid in the affected areas was unable to handle the load.

The blizzard was described as “unprecedented,” and knocked out grid-supplied power to more than 1.8 million customers at the peak of the storm. The fortunate were those homes and businesses that have a solar pv system with battery backup.

Insider reports:

“Freezing temperatures from the ongoing winter storm sweeping the United States have prompted some utility companies to institute “rolling blackouts” to keep power systems from failing.

In the South, the Tennessee Valley Authority announced Saturday morning that it was asking local power companies to “reduce load” due to “continued unprecedented cold temps resulting in high power demand.” The TVA services all of Tennessee. Parts of Alabama, Mississippi, and Kentucky, and small areas in Georgia, North Carolina, and Virginia are also powered by the TVA.

“Planned intermittent interruptions support system reliability,” the company said in a tweet. “We appreciate everyone’s patience and support as we manage this unprecedented demand.”

The TVA began instructing local power companies to reduce power usage on Friday night, and some have instituted rolling blackouts in some cities such as Nashville, Tennessee. Some local power companies have also started using rolling blackouts after the TVA asked them to reduce power usage.” 

https://www.insider.com/us-utility-companies-apply-rolling-blackouts-due-to-freezing-temps-2022-12

You can read the entire story at Insider.com.

In A Power Generation Emergency, New England Resorts To Oil

Power Grid

The Christmas weekend storm brought more than just severe weather to New England. It also brought severe stress to the region’s power grid.

In times of normal electricity demand, New England doesn’t rely at all on oil as a fuel for power generation, and chooses less expensive nuclear, natural gas, and hydro and solar.

It is only when it has to, does the region fall back onto oil.

This weekend was one of those times.

On Christmas Eve, oil fired power generation was accountable for as much as 40% of the grid’s needs.

Bloomberg reports:

Oil took over from natural gas as the leading fuel for power plants in New England, a significant switch that signals how the grid is desperately trying to keep the lights on in the face of a winter massive storm.

The six-state grid relied on oil for at least a third of its power generation and for as much as 40% at times on Saturday, ISO New England data show. Natural gas provided as little as 15% by mid-afternoon.

The region typically only uses oil to meet demand on the hottest and coldest days of the year as back up. Heading into the peak evening hours, New England issued a series of grid alerts warning of a possible shortfall of power reserves and asked market members to voluntarily conserve electricity. 

The operator later said it’s trying to buy emergency supplies from market participants or neighboring regions. The situation is so tight that prices jumped to more than the $2,000 a megawatt-hour price cap on Saturday evening. This time last week, spot power was in the $30 range.

https://www.bloomberg.com/news/articles/2022-12-24/storm-elliott-news-oil-is-main-fuel-for-power-plants-in-new-england?leadSource=uverify%20wall

You can read the full story at Bloomberg.com.

Obscure Bottleneck Preventing Clean Energy Access For Millions of People

Clean Energy, Power Grid, Solar Energy

If given the choice between clean energy, and pollution-laced energy sources, the vast majority of people would opt for the former. As we previously reported, the solar industry is experiencing tremendous growth.

There is, however, one obscure bottleneck that is hindering the growth of the solar industry in the U.S. in a very, very, very significant way.

The demand from the public is there. Developers are there with proposed projects to meet demand. The problem lies with the ability to connect those proposed renewable energy projects to the grid.

The Washington Post reports:

To achieve America’s goal of shifting 80 percent of the country’s electricity away from fossil fuels by the end of the decade, there will have to be a massive transformation. That means solar farms peppering the landscape from California to New York; offshore wind turbines standing high above the waves off the coast of New Jersey; nuclear power plants emitting steam in rural areas. Together, these projects would have to add around 950 gigawatts of new clean energy and 225 gigawatts of energy storage to the grid.

And right now, projects accounting for at least 930 gigawatts of clean energy capacity and 420 gigawatts of storage are waiting to be built across the country.

They just can’t get connected to the grid.

These roadblocks — known as “interconnection queues” — are slowing America’s energy transition and the country’s ability to respond to climate change.

“It’s a huge problem,” said David Gahl, executive director of the Solar and Storage Industries Institute, a research group affiliated with the solar industry. “If we don’t make changes, we’re not going to meet state and federal targets for climate change.”

To understand the lines blocking the U.S.’s progress on climate change, you first have to understand a bit about how the electricity grid works. It’s easiest to think about the grid — which carries electrons — like the country’s roads carrying cars.

When an energy developer wants to build a new power plant, they have to submit an application to see how adding that facility will affect the grid — sort of like trying to build an on-ramp onto a big interstate highway, according to Joe Rand, a senior engineering associate at Lawrence Berkeley National Laboratory.

Regional authorities have to check to make sure that the highway can accommodate a new on-ramp without causing traffic pileups. In the same way that an authority might ask the road-builder to pay for the construction of the on-ramp — or, if the highway is really congested already, to pay to add an extra lane — regional authorities ask energy developers to pay to connect their solar or wind farms to the grid.

Getting the okay to connect has gotten harder and harder. According to Rand’s research, between 2000 and 2010 it took around two years for a project to make it through the queue. Now, it’s taking almost twice as long. At the end of 2021, there were 8,100 projects sitting in line, waiting for permission to get connected. Together, they represent more than the combined power capacity of all U.S. electricity plants.”

https://www.washingtonpost.com/climate-environment/2022/12/20/clean-energy-bottleneck-transmission-lines/

You can read the full, fascinating story here.

Iron-air batteries could store and discharge energy for far longer and at less cost than lithium-ion

Energy Storage, Power Grid, Solar Equipment

A new battery design holds out the potential for great improvements over the current industry leading lithium-ion battery.

Designed by a Massachusetts company that is run by a former Tesla executive, the battery technology could be far less expensive, as well as increase the discharge time from the current 4 hours of Lithium-ion to 100 hours.

The founders of the company share a goal to reshape the global electric system by creating a new class of low-cost multiday storage batteries.

The implications for solar energy systems are nothing less than breathtaking.

Scientific American reports:

“A U.S. company is designing a large battery that it says could help decarbonize the nation’s power sector more cheaply than lithium-ion storage systems—and with domestic materials.

The concept, known as the “iron-air battery,” has impressed U.S. experts. Unlike current lithium-ion batteries that require expensive materials mostly from other countries such as lithium, cobalt, nickel and graphite, the proposed battery stores electricity using widely available iron metal.

It operates on what scientists call the principle of “reversible rusting.” The low cost and high availability of iron could allow iron-air batteries to store electricity for several days during periods of low solar and wind power generation. One such iron-air battery is being designed by Form Energy, a company based in Massachusetts that’s co-run by a former Tesla Inc. official.

Although iron-air batteries were first studied in the early 1970s for applications such as electric vehicles, more recent research suggests that it may be a “leading contender” to expand the nation’s future supplies of green electric power for utilities, according to George Crabtree, director of the Joint Center for Energy Storage Research at Argonne National Laboratory.

Lithium-ion batteries, which are used in cars and for utility-scale storage, discharge electric power for about four hours. The much larger iron-air battery can store and then discharge power for as long as 100 hours, giving utilities four days of electricity to bridge renewable power gaps that can occur in U.S. grids.

Crabtree, a physicist, predicted that the iron-air battery would also help the U.S. decarbonize industrial operations and buttress the Defense Department’s plans to rely more on renewable energy.“

https://www.scientificamerican.com/article/rusty-batteries-could-greatly-improve-grid-energy-storage/

You can read the entire story at Scientific American.

North American Electric Reliability Council Report Warns of Elevated Risk of Blackouts

Power Grid

The North American Electric Reliability Corporation (NERC) has just released its 2022-2023 Winter Reliability Assessment Report.

At highest risk of winter blackouts are Texas, North Carolina, New England and the Great Lakes region. The 43 page report concluded that a “large portion” of the U.S. power grid could be subject to insufficient electricity supplies in times of peak winter demand.

Some analysts point to climate change as the primary culprit, while others attribute the potential electrical supply shortfall to bottlenecks and restrictions on fuel supplies.

Regardless of the exact cause, most analysts agree that the elevated risk of blackouts is a matter of serious concern.

Experts warn that solving the complexities of the power grid will take years, not months.

The risk of going without power for a period of time is just one of several very powerful motivators that is driving the surge of demand for home solar panel installations.

You can download the 43 page NERC report here.

Two New Warnings Of Potential Power Cuts This Winter

Power Grid

Warnings of potential power cuts/outages by utilities and governments around the world are becoming more frequent – to the point where hardly a day goes by without a new warning being issued somewhere.

Here in the United States, we are not immune to potential brownouts and blackouts due to inadequate supply.

Just today, the New York Times published a story titled, “Advice for Europeans: Bundle Up and Get Ready for Outages.”

Liz Alderman, reporting from France, starts the story by bluntly stating:

“Life in some European cities may soon look like this: Staggered electricity outages to save energy.” 

New York Times, Dec 5, 2022

She went on to warn:

“governments are starting to brace people for the possibility of controlled power cuts in the event that energy supplies are stretched — with a wide-ranging impact on daily life.”

And just a few days ago, Xavier Piechaczyk,  the head of grid operator RTE in France, warned that:

“France could face the risk of power cuts this winter when electricity supply may not be enough to meet demand”

Oilprice.com, Dec 1, 2022

Here at Pine State Solar, we passionately wish that the trends of skyrocketing electricity prices and power from the grid becoming increasingly unreliable were not happening. But we are realists and acknowledge that those trends are, indeed, occurring.

The solution to both soaring electricity rates and the supply of grid power becoming more sporadic is to install a solar panel system with battery backup at your home or business.

We’re here to help. Give us a call for all your solar power needs.

New York Power Company Issues Warning of “Sharp Rise” In Electricity Prices

Power Grid

As we have mentioned in our article about solar panels being an inflation hedge, just today another warning has been issued that the sharp rise in electricity prices in not a thing of the past, and that consumers in New York can expect further sharp rises in the months ahead.

New York Independent System Operator (NYISO) today attributed the future price increase to geopolitical tensions along with national and international economic conditions. NYISO stated:

The New York State bulk electric system is well positioned to meet this winter’s forecasted demand and maintain reliability throughout the season,” said Aaron Markham, Vice President of Operations for the New York ISO. “However, as we have been highlighting for over a year, national and international economic conditions are contributing to a spike in consumer bills.

NYISO went on to predict:

The NYISO is warning of a sharp rise in wholesale electricity prices expected this winter due to several economic and geopolitical factors that continue to impact the cost of natural gas used in the production of electricity.

As part of its effort to prepare consumers and policymakers for this winter, the NYISO released an updated white paper in September that explores the cost drivers behind commodity increases of the past year and predicts further commodity cost increases this winter.

Electrical prices are rising globally, and these price rises are not unique to New York and New England.

You can read the full press release from NYISO here.