Can Battery Storage Become Competitive?

I have been a battery storage skeptic. While proponents of wind and solar energy talk about going 100% renewable, my estimates top out at about 20% wind, 12% solar, 8% hydropower and 5% other. To get more than that, you need electrical energy storage, and right now that is very expensive. I have estimated that the cost of battery storage is about 25 times the cost of building back-up natural gas generation, and it didn’t look like that was going to change soon.

Historic Lithium Ion Battery Prices

Estimates of lithium-ion battery cost vary widely, but have been decreasing by only 8% to 14% annually. That rate halves the cost every 5 to 9 years. Bringing the cost down 25 times would take 25 to 42 years if current rates held, and they are unlikely to hold over that period of time.

Meanwhile, despite lithium-ion batteries showing up in all sorts of mobile devices including cell phones and automobiles, the mining of lithium has been growing at only about 7% per year. I have seen various reports of breakthroughs in batteries including alternate chemistries including aluminum-air, more stable mixtures including lithium-phosphate, different geometries and various anode-cathode designs, but none of them has fundamentally changed the basic lithium-ion battery.

Then Elon Musk, CEO of the electric car company Tesla, proposed to build his battery gigafactory. He wasn’t counting on any battery breakthroughs, but aimed to bring down the cost of lithium-ion batteries 30% or more by sheer mass production. Eleven months ago he announced a location in Nevada. The factory isn’t even built yet and now I am hearing unconfirmed reports of a 70% drop in lithium-ion prices. His competitors have stepped up in anticipation of a surge in sales of electric vehicles, and prices have fallen.

Meanwhile, installations of customer-side energy storage were up 3X from 2013 to 2014  and utility-side battery storage installations in the second quarter of 2015 were up 9X from the same quarter in 2014.  Battery storage is still very expensive, but my assumptions in the first 2 paragraphs of this letter are being reconsidered.

Utility-Scale Solar in North Carolina

The number 2 state for new solar installations last year was North Carolina with 397 Megawatts of capacity. Nearly all of that new capacity was from utility-scale installations.

2014 Photovoltaic Installations by State

Strata Solar  is one big player, having installed 500 MW already and 1,000 MW more under development. Duke Energy is another.

There are a number of reasons for the growth of utility-scale solar in North Carolina with rules that favor the big corporations. Tax credits and guaranteed income are the keys.

The federal government offers a 30% tax credit on new solar installations that is due to drop to 10% after 2016. The state of North Carolina offers another 35% tax credit on top of this. So anyone trying to install new solar facilities can qualify for 65% in tax rebates pushing down their costs down to just 35 cents on the dollar. The cost to install a megawatt of solar cells, normally around $3 million, drops to about $1 million. That’s good news if you have access to millions of dollars. However, the state does not allow solar leases, so if a homeowner wants to have a $20,000 rooftop solar system on his house, he has to pay out the whole $20,000 and then claim the $13,000 credit on his taxes. That’s more than the average homeowner can swing.

The guaranteed income comes in the form of a 15-year contract with the utility company. The state has streamlined the process to becoming a “qualifying facility.” Qualifying Facilities under 5 MW can get 15-year contracts with the local utility company (Duke Energy) at the utility’s “avoided cost.” Do the math, and it’s a guaranteed way to make money that you can take to the bank.

For three more reasons for the growth in North Carolina solar, see

Political Tide Turning Toward Solar

In the latest political wrangling over rooftop solar power, it’s the career politicians and the utility companies on one hand and environmentalists joined by tea party conservatives on the other. The current struggles in Indiana and Florida highlight a rising solar movement asserting itself against political backroom deals.

Map of Indiana solar potentialIn Indiana, the traditional electric utility companies want to raise “tariffs, rates and charges” on customers who generate their own electricity. The lobbying group for the utility companies, the Indiana Energy Association, has gotten Republican Rep. Eric Koch to sponsor their legislation to allow them to charge customers who generate their own electricity these tariffs, rates and charges not imposed on other customers. Mr. Koch is a big player in Indiana politics, being the Assistant Majority Caucus Chair. Mr. Koch has been in the Indiana legislature since 2002 and currently serves as the Chair of the Energy, Utilities and Telecommunications Committee. Needless to say, raising the fees charged to customers with their own solar systems would discourage those customers from installing more solar power.

Opposing the legislation is the state chapter of the NAACP, the Citizens Action Coalition, the Center for American Progress, the Alliance for Solar Choice, and the Sierra Club. Conservatives arrayed against the bill include the Christian Coalition for America, and Barry Goldwater Jr’s Tell Utilities Solar Won’t Be Killed (TUSK)  . Churches against the bill include the seven congregations of Indianapolis’s Eastside Creation Care Network.

The Energy, Utilities and Telecommunications Committee has approved the bill and passed it on to the whole House after denying 34 of the 42 people signed up to speak against the bill an opportunity to give their testimony. It was a straight Republican party-line vote, but clearly some Republicans aren’t happy. Indy Star

Welcome to Florida sign, the Sunshine State

Meanwhile, Republicans in Florida have organized a ballot initiative to allow homeowners to enter into solar power purchase agreements. Under a typical solar power purchase agreement, the homeowner allows a company such as SolarCity to install solar panels on their roof and agrees to buy the power from those panels at a rate lower than that offered by the local electrical utility.  It’s an attractive arrangement – no money down, lower your monthly payments and help the environment. But Florida law prohibits the sale of electricity to consumers by anyone other than a regulated public utility. Each utility company has their designated service area and operates as a monopoly within that service area.

Floridian Tea Party members have now organized the Conservatives for Energy Freedom which is aiming for more than 700,000 signatures on a petition for a 2016 ballot initiative which would make it possible for businesses and property owners to produce up to 2 megawatts of solar power and sell it directly to consumers.  The group Floridians for Solar Choice has gathered endorsements from conservative groups including the Christian Coalition of America, Florida Alliance for Renewable Energy, Florida Retail Federation, Florida Solar Energy Industries Association, Libertarian Party of Florida, Republican Liberty Caucus of Florida, Republican Liberty Caucus of Tampa Bay, Southern Alliance for Clean Energy, WTEC  and support from groups across the political spectrum including Clean Water Action, Environment Florida, Evangelical Environmental Network, Greenpeace USA, IDEAS for Us, Physicians for Social Responsibility, ReThink Energy Florida, Sierra Club Florida, and The Tea Party Network. They’re also getting support from the conservative Heartland Institute and constitutionalist Hillsdale College.

Fresh Water from the Sun and Waves

Clean water is still hard to get for many of the poorest people of the world living in underdeveloped countries. Bangladesh now has more people than Russia, and most of its people suffer from water that either leads to dysentery and disease or contains dangerous levels of arsenic. Millions of others live along the seacoast where water is all around, yet not fit to drink. Desalinization is expensive and energy intensive. But two research projects have the potential to bring clean fresh water to millions using solar or wave power.

A British company has produced now 4 prototype solar powered desalinization units they call the Desolenator. The family-sized unit has a single insulated solar panel measuring about 3 feet by 5 feet and produces about 4 gallons per day of distilled water. Desolenator unit

The company is still in the development stage optimizing the product and plans to produce 100 units in the first half of 2015, scaling up to 1000 units in the second half. They are currently raising $150,000 for refining the process on Indiegogo. The unit produces about 4 gallons per day and costs under $500.

In Quebec, students at Sherbrooke University are working on using wave power to desalinate sea water by reverse osmosis. The students are designing a second prototype unit designed with a buoy on top and an anchor below to desalinate 925 gallons per day. The wave motion drives a hydraulic cylinder pump that pushes the seawater through a reverse-osmosis membrane and pumps the fresh water to shore.Odyssee desalinator

The students are now raising $8,600 on Kickstarter to fund construction and testing of the second prototype.

China Tries to Clear the Air

China’s rapidly growing manufacturing economy requires lots of electricity. Historically China has met their electrical requirements by building coal-burning power plants. China does have some nuclear power, but coal has been the mainstay.

Graph of China's coal usage compared to the U.S.

In 1994, China began construction on the world’s largest hydroelectric dam across the Yangtze River. The Three Gorges Dam project took eight years to become operational and displaced 1.3 million people.

Polluted air at Tianamin SquareHydropower was a nice idea, but it couldn’t keep up with China’s rapidly growing economy. So many coal-burning power plants were built that by the time the Three Gorges Dam was up and operating, the air in Beijing was thick with smoke.

Graph of wind power installed capacity in leading countries
So China has aggressively pursued wind and solar power. The nation is already number 1 when it comes to wind power.

In fact, China has been building wind towers faster than the can connect them to the grid.

Graph of installed solar power capacity in leading countriesNow they’re doing the same with solar power.

Swanson’s Law states that every doubling of photovoltaic (PV) solar capacity results in a 20 percent reduction in unit cost. China aims to make solar power cheaper than coal by brute force. China plans on adding another 13,000 megawatts this year hitting 35 gigawatts in early 2015 and targeting 100 gigawatts by 2020. Last year China also added 13,000 megawatts of solar power. However last year 94% of that came from large utility-scale solar farms. This year China is trying to get over half of the new solar power from small projects. Michael Sankowski estimates that solar in China will become cheaper than coal by about 2018. That cost reduction will not only benefit China, but solar installations all around the world.

China’s commitment to reducing its carbon emissions announced during President Obama’s visit last month requires some massive spending by the Chinese government. Bloomberg news estimated that it would require “either 67 times more nuclear energy than the country is forecast to have at the end of 2014, 30 times more solar or nine times more wind power.”

But with China it is not either/or. Besides solar and wind, the nation also plans to almost quintuple its nuclear power in the next 5 years. Currently with 18 gigawatts of nuclear power, China plans to add 58 gigawatts of nuclear power by 2020 and have another 30 plants under construction.

3-D Printing Organs

It may sound a little like Frankenstein, but scientists are working on being able to use 3-D printing technology to create human organs. Today’s post is going to make heavy use of video, but in this case, a video clip is worth a thousand words.

For background, check out this 3-year old TED talk and then come back for an update.

At the University of Louisville, researchers are working on 3-D printing a human heart.

Creating a whole new heart is years away, but heart valves are already being produced. And 3-D printing is helping surgeons prepare for complicated heart surgery.
Using MRI scan data, Morgan Stanley Children’s Hospital in New York City 3D printed a copy of the child’s heart, which was both riddled with holes and structured unusually.
Surgery was going to be complicated and dangerous, but this 3D printed heart [model] provided the surgeons the opportunity to study the organ, and develop a detailed surgery strategy.

Companies like Organovo are producing human tissue samples for the testing of new drugs.

Liver toxicity is a key concern for any new drug and Organovo is selling samples of human liver tissue to drug companies for their use in testing possible drugs.
Aspect Biosystems in Canada is also working on creating 3-D human tissue samples.

Research is underway on a number of human organs. The goal is to use a patient’s own cells to grow the new tissue and organs that will be transplanted back into the patient’s body. One of the difficulties is including blood vessels in those organs. Dr. Jennifer Lewis at Harvard has now come up with a way to 3-D print with multiple cell types including the cells that form blood vessels. She was able to create blood vessels down to 75 micrometers in diameter. Technology is not yet available to get down to true human capillaries which average only 8 microns in diameter. That size is necessary for good oxygen transfer from the red blood cells to the surrounding tissue.

Stacking up the Solar Energy Credits in Massachusetts

Massachusetts may not be the first place you think about when it comes to solar power, but due to a series of government incentives it can be a very profitable place to build a residential solar power system.

graph of Massachusetts electric rates since 2001As I discussed in Solar About to Go Mainstream,  one of the principal factors in deciding to build solar facilities is the cost of the regular power from the utility company. Because of the island’s dependence on oil for power generation, Hawaii has the nation’s highest electric rates and has been a leader in residential solar power. In Massachusetts, the electric rates are skyrocketing. One of their utility companies, National Grid, has raised winter residential rates this month to 24.2 cents per kilowatt hour. That’s over twice the national average.

Western Massachusetts Electric Company has asked for a rate increase of 29%.

California’s solar growth can be attributed to the state’s aggressive Renewable Portfolio Standard requiring 33% of power from renewable sources by 2020. As discussed in California Solar Power and the “Duck Curve” 30 states have adopted Renewable Portfolio Standards. The Renewable Portfolio Standard in Massachusetts is 9% this year and scheduled to increase by 1% per year. Massachusetts also has a solar “carve out” designed to support up to 1,600 megawatts of solar power in the state by 2020. That’s equivalent to 320,000 homes at 5 kilowatts per house. The state is already almost halfway there. Graph of Installed solar capacity in Massachusetts

Connecting a residential solar power system to the grid allows power to flow both ways. At night, when the sun isn’t shining, the homeowner draws power from the grid. During the day, if the amount of solar power generated exceeds what is being used in the house, the power flows out into the electric system, feeding the needs of the neighbors. map of states with net metering policiesUtility billing practices that give the homeowner credit for the excess power generated and fed into the grid are called “Net Metering Policies.” Currently 43 states have mandatory net metering policies and three states have voluntary net metering.

So faced with high and rising electric bills and living in a “solar friendly” state, what can a homeowner in Massachusetts do?

One option is called a “solar lease.” If your house has a south-facing roof and little shade, companies like Solar City will install solar panels on your roof for free. Then they will sell you the power generated at a rate lower than the utility company locked in for the next 20 years. Solar City handles all of the permits, installation and maintenance. Under the lease agreement, Solar City owns the panels on your roof and you get the power at a discount.

But I’ll show you a better way.

The average home in Massachusetts uses 627 kilowatt hours of electricity per month. Installing a 5,000 watt solar system will produce 2/3 of that amount on average. If you’re efficient, that might be enough, but for our example, let’s be generous and figure a 7,500 watt system to provide for all of your needs.
Average cost of residential solar systems 2014
According to the Solar Energy Industries Association, the latest average cost for a residential rooftop power system is $3.74 per watt. A 7,500 watt system would cost about $28,000. That sounds like a lot, and it is.

Now let’s consider the credits. For starters, there’s a 30% federal Residential Renewable Tax Credit. So take off $8,400 to bring the price down to $19,600. Then the state of Massachusetts offers a base incentive of 25 cents per watt for the first 5,000 watts which comes to $1,250. If your household income is less than 120% of the median household income, Massachusetts kicks in another 40 cents per watt or another $2,000. Subtracting the $3,250 from the state brings the system cost down to $16,350. That’s still a large chunk.

Once the system is up and running, however, you’ll save about 625 kilowatt hours per month that would otherwise be paid to the power company. At 24.2 cents per kilowatt hour, those savings amount to $151 per month or $1,812 per year. With that, the system will pay for itself in 9 years.

But there’s more. Your system generates an estimated 7,500 kilowatt hours per year. Each 1,000 kilowatt hours earns you one Solar Renewable Energy Credit (SREC). These are separate from the power you already used in your home. Let’s round that down to 7 SRECs. These SRECs can be sold at auction and the utility companies are required to buy them to meet the state’s Renewable Portfolio Standard. At the latest auction, Massachusetts SRECs sold for $274 each. Your 7 SRECs would be worth $1,918.

When you consider the $1,812 per year in savings from your electric bill and $1,918 in Solar Renewable Energy Credits, the system pays for itself in less than 4 ½ years, and thereafter you not only have free electricity, but the system pays you. Even if you have to take out a home equity loan to pay the upfront costs, unless you plan on moving in the next 5 years, it’s a deal too good to pass up.

Disclaimer: this is not investment advice. The values here are for illustration only and your results will vary. This is not an endorsement of Solar City or any other solar supplier or installer. Electric rates and the value of Solar Renewable Energy Credits may go up or down. The 30% Residential Renewable Tax Credit is scheduled to be reduced to 10% after 2016 and may be changed at any time by an act of Congress. Do your own research before investing.

Supercomputing Power in Gaming Graphics Accelerators

Today’s video games use computing power that was achieved only by supercomputers just a few years ago and the makers of computer graphics cards have risen to the challenge. Screen resolution continues to climb and the visual effects get bigger and better.

Nvidia Tesla graphics card
AMD’s Radeon series and Nvidia’s GeForce series graphics accelerators achieve the effects by dividing the computations between hundreds, or even thousands of GPUs or Graphics Processing Units.

Nvidia’s graphics chips also process the physics equations involved in explosions, shock waves and ricochets.

While the performance of the main processors in computers continues to improve, the speed of the GPUs is now several times faster. As a result, when the US government decided to build the world’s fastest supercomputer, they recently chose a design that incorporates thousands of Nvidia GPUs.

The Department of Energy just signed a deal with IBM and Nvidia to build two supercomputers for the Oak Ridge National Laboratory and the Lawrence Livermore National Laboratory featuring thousands of IBM servers and even more Nvidia graphics accelerators based on the Tesla platform pictured above. The total value of the deal is with $325 million, far above the average video gamer’s budget. Nvidia further accelerates the processing by stacking the RAM memory on the GPUs. The new supercomputer named “Summit” at Oak Ridge will be capable of 150 to 300 petaflops (quadrillion floating point calculations per second).

The cutting-edge same technology is not only available to video game players, but it may be coming to an automobile near you. Nvidia has partnered with automakers worldwide including Audi, Honda, Tesla and Volkswagen for infotainment systems, navigation and collision avoidance systems.

House Approves the Keystone Pipeline, Senate Vote Next

While oil production has been booming in Texas and North Dakota in the US, a smaller boom has been going on in the oil sands of Alberta, Canada.

Alberta has 168 billion barrels of proven petroleum reserves locked up in thick, tarry sand deposits known as the Athabasca oil sands. The oil formation is the world’s third largest. These deposits are either strip-mined when close to the surface, or steam is injected into the ground, causing the thick bitumen to flow to parallel wells. The extraction is not cheap or easy, but has been increasing.

One pipeline company, TransCanada, proposed the Keystone XL pipeline in September, 2008 to carry up to 830,000 barrels per day from Alberta to the Texas gulf. In 2010, Montana Governor Brian Schweitzer negotiated a deal to reserve 100,000 barrels per day for crude from Montana and North Dakota, leaving 730,000 barrels per day of capacity left for Canadian oil.
US oil imports from Canada and Saudi Arabia since 2000
Although the Keystone XL pipeline has become a political issue, the delay in building the pipeline has not prevented the development of the Alberta oil sands or kept the oil from crossing the border. When the pipeline was proposed, US oil imports from Canada were running about 2.5 million barrels per day. Now, those imports are running about 3.25 million barrels per day, 750,000 barrels per day higher. A product in demand tends to find its way to market one way or another.

Some of that Canadian oil has been carried by rail. Canadian oil exports by rail have risen tenfold from 16,000 barrels per day in the first quarter of 2012 to 165,000 barrels per day in the first quarter of 2014. Some 50,000 more rail tank cars are on order and expected to be manufactured over the next two years. 100 tank cars stretches about one mile; 50,000 tank cars joined end-to end would stretch 500 miles. Many of the cars on order are of the “coiled and insulated” type designed specifically to carry heavy, thick Alberta bitumen. Once they reach their destination, steam is injected into the coils to warm the bitumen enough that it can flow easily and drain from the rail car. In conventional rail tank cars, the bitumen needs to be diluted about 30% with a lighter, thinner petroleum product called a diluent. The diluent is also used in pipelines to help the thick, gooey stuff flow.

The need for diluent has created a series of “parallel pipelines.” The US ships the diluent north in one pipeline. Canada mixes it with their thick bitumen and pipes it back south.

Because the delays in approving the Keystone XL have exposed a critical dependency on the US for Canadian oil exports, Canadians are preparing to take control of their own exports by shipping oil to their own east or west coasts. TransCanada has recently proposed the Energy East pipeline to carry up to 1.1 million barrels per day from Alberta to St. John, New Brunswick, where the oil can be loaded on tankers and shipped to India. Canada’s National Energy Board has also approved a 525,000 barrel per day pipeline proposed by competitor Enbridge to carry crude from Alberta to Kitimat, British Columbia for export to east Asia. And Kinder Morgan has proposed to build a parallel pipeline to their Trans Mountain pipeline to Vancouver to nearly triple the capacity from 300,000 barrels per day to 890,000 barrels per day. All four proposed pipelines face opposition but one or more of them is likely to be built. There’s a lot of money behind them and money talks in Washington, Ottawa and Victoria.

In Washington, the House has once again voted to approve the Keystone pipeline. In the Senate, Louisiana Senator Mary Landrieu (D) is facing a runoff election on December 6th. Chances that she will keep her seat look slim, but as chairman of the Senate Energy and Natural Resources Committee, she expects to finally get the Senate to vote on the Keystone issue which was first approved by the House in July 2011. If passed, it’s unclear if the President will sign the legislation.

At the moment, there seems to be plenty of oil to go around in the world, and the price has dropped by over 30% since June, down to about $75 per barrel. Canadian oil sands are among the world’s most expensive to produce. At this price, Canadian production might take a bit of a breather. The Keystone XL, even if approved next week, won’t be in operation until 2016. The Trans Mountain expansion won’t be in operation until at least late 2017. Enbridge’s Northern Gateway won’t be in operation until at least 2018. TransCanada is also hoping for a 2018 start of operation for the Energy East pipeline to New Brunswick. Numerous court challenges are likely to delay each of these projects. But chances are, by the time one or more of the pipelines get built, oil prices will have risen again and Canadian oil production will have a ready market.

California solar power and the “duck curve”

Last week as I wrote in Solar about to go mainstream,  I told you about one state where solar has already gone mainstream with over 10% of homes already having solar panels on their roofs. That state, Hawaii, not only has abundant sunshine, it also has the highest regular electric rates in the country. This week the discussion moves to the continental United States and the one state with more solar power facilities than all the others put together, California.

Map of states with a renewable portfolio standardCalifornia, Hawaii, 35 other states and the District of Columbia have created Renewable Portfolio Standards specifying a minimum level of renewable fuel sources for their electric utilities. In seven of the states the Renewable Portfolio Standards are voluntary, rendering them merely symbolic.

In 30 states, however, the standards are mandatory. The Illinois standard, adopted in 2007 is for 25% of electricity from renewable sources by 2025, sometimes known as a 25 x 25 standard. In Michigan, the standard is 10% from renewable sources by 2015. California has probably the nation’s most aggressive Renewable Portfolio Standard requiring 20% of all electric power from renewable sources in 2010 and 33% in 2020.

Cummulative California Photovoltaic Installed Capacity
Solar power installations in California more than doubled last year.

Of course, solar cells can only generate power when the sun shines. There’s little power in the early morning hours or late afternoon, and none at all after the sun goes down. Coal burning power plants typically have capacity factors greater than 80%, with only short shutdowns for maintenance. Wind turbines have capacity factors of about 40% depending on location. Solar cells are rated for direct sunlight on a clear day at noon and generate less all other times of the day, when it’s cloudy or even when the panels are dusty. A capacity factor of only 12% to 13% is typical.

California ISO Solar Power Duck GraphModels of the effects of future solar power generation in California have resulted in the California “duck graph.”

Solar power reduces the amount that needs to be generated from other sources during the day, but drops off rapidly after 4 pm and does nothing to help meet peak power requirements between 6 and 10 pm. As more solar power is installed, the belly of the duck gets deeper and the utility must bring up other sources of power quicker after 4 pm. Coal power plants can’t start and stop quickly and nuclear power is steady all day long. Winds tend to pick up in the hours around dusk and dawn as the temperatures change, but wind is unpredictable. That leaves natural gas (and hydro power to some extent) to make the quick transition.

Aerial photo of Ivanpah thermal solar power facilityOne potential solution is thermal solar power. California built the world’s largest thermal solar power generating facility in the Mojave Desert last year. Thousands of mirrors reflect sunlight to water tanks at the top of tall towers, turning the water to steam which drives turbines to generate electricity. One of the advantages is that the steam stays hot for hours after the sun goes down and the facility continues to generate power into the evening hours.

However, more facilities like the one pictured above at Ivanpah, California are unlikely to be built for several reasons:

  1. The facility is killing approximately 2,000 birds per month, heating them to 800 degrees as the fly through the air.
  2. Pilots flying overhead are complaining about the blinding glare.
  3. The cost of regular silicon solar cells continues to come down. While thermal solar was expected to be cheaper than regular solar panels when it was built, that is no longer the case.
  4. The project is only generating ¼ of the amount of power that was expected. The project investors, including Google, who got a $1.6 billion federal loan to build the facility are now asking for $539 million federal grant to help pay off the loan.

Solar vs grid power costRemember this graph from last week?

The price of large utility-scale solar power facilities has come down much faster than smaller residential rooftop setups. The major difference is the cost of inverters which turn the direct-current from the solar panels into alternating current and synchronize it to the grid. For a residential system, these electronics can be more expensive than the silicon panels themselves. The inverters are a much smaller portion of the cost for large systems. As a result, most solar power installations in the US last year were utility-scale systems.

Solar power installed in 2013 by state

Many environmentalists talk about the “distributed generation” of rooftop solar systems and the end of the grid as we know it. With a distributed generation model, the grid becomes less and less important as power is generated in the same neighborhood (or even the same building) as it is needed. But even as solar power escalates around the country, the reality is very different. Three out of four homes are not well suited for solar, either due to roof geometry, shade, or other issues. And solar power installations are increasingly large-scale facilities far from populated areas where land is cheap, feeding directly into the grid. Wind power too, is mostly located in rural areas, thousands of feet from the nearest home. We will need the current electrical grid for a long time to come. In fact, due to the variability of renewable power sources like wind and solar, the grid will need to be even more robust than it is today.