Support solar. Just don’t put it on your house.

Last night my wife and I spent approximately $12 plus an hour of time to make 24 cupcakes. I couldn’t help but wonder how much it would have cost just to buy 24 cupcakes. This question frequently comes to mind when I think about DIY home repair, or DIY furniture making (something I expect to take on this weekend). Considering cost, time and quality, is it really better to do it myself? Hard to say.

When you get to solar, however, the answer looks a little more obvious. Should I generate my own solar energy or let the professionals do it? Intuitively I always knew residential solar had to be less efficient than commercial arrays, but nevertheless I was shocked when I saw these actual figures in a recent NREL paper.

Installed Costs ($/watt)
$5.50 residential
$4.00 small commercial
$3.00 large commercial/industrial

Residential solar – nearly twice as expensive per watt! The economist in me cringes at all the waste implied by that $2.50 spread (wasted materials, energy and of course labor). There might be an argument based on local sustainability for mid-sized arrays such as solar gardens or solar on top of the local Walmart, but not for solar on my roof (actually I don’t have my own roof, but I’m speaking theoretically here).

Whether I look at solar as an investment, or as a way to help the environment, scattering it here and there on people’s rooftops just doesn’t seem to make sense.

As a note, full cradle to grave efficiency could be even worse if the calculations didn’t include variance in operating efficiencies caused by seasonal cleaning and azimuth adjustments (both I expect are far less likely on residential systems). These figures only appeared in a supporting table of the report, so I don’t know the study methodology, but either way, the difference is clearly huge.


A Taste of the Coming Challenge

Here’s an informative article from Bloomberg about the tension between utilities and residential solar installations, mostly focused on Hawaii.

The problem for the utilities is that the current grid is designed to send power downstream from large power plants to houses and businesses.  With so many power consumers suddenly becoming producers, the grid is becoming back-fed, something it hasn’t been designed for.  The Hawaiian utility (HECO) recently stopped any new solar installations from being connected to the grid while they study the potential impact.

From the article:

The issue, according to HECO, is that for about 20 percent of Oahu’s grid there is so much solar connected you can’t add more without further study because of the potential for reliability and safety issues. Solar advocates have said the figure is arbitrary.

Arbitrary or not, it means new solar customers must await engineering studies to determine if they can connect without causing surges that may damage appliances, electronics or utility equipment. Some might have to pay for utility equipment upgrades that could cost thousands of dollars before getting approval to connect.

“This is about safety,” said Scott Seu, HECO vice president for energy resources and operations. “We are so far ahead of the rest of the nation as far as the amount of distributed rooftop solar in our neighborhoods that we are now at points where there are potential safety and operating liability issues.”

Most of the grid is designed to deliver electricity downstream, from large power plants to  consumers. But when a lot of people start putting power back into the system, the utility starts having a lot more problems keeping the electricity flow consistent – avoiding spikes, troughs, and overloads.

Most transformers are designed to convert electricity from high voltage lines down to local lines – not the other way.  The wires inside most transformers are not symmetric, so they are more likely to overheat and even explode when a lot of energy is running through the system backward.

The utilities need to upgrade their equipment on the grid to handle this.  It’s much like the cable companies moving from only sending TV downstream to providing two-way Internet connections.  Of course, this is very expensive and the utilities will fight tooth and nail to avoid it as long as possible.

Few Electric Vehicles Even in 2040

The Federal Government just released a number of predictions about energy in its Annual Energy Outlook 2014, early release overview.  Here are some highlights:

  • US oil production is approaching all-time highs and should peak around 2016 at 9.5 MMbbl/d, then level off and start decreasing again around 2020.
  • Natural gas is abundant in the US and should continue to grow through 2040.
  • Americans will continue to drive a bit less and cars will continue to get more efficient, decreasing demand for oil.
  • Oil prices will be between $50 and $200 in 2040 with about $150 most likely.
  • By 2040, they predict that natural gas will produce 35% of US energy and coal will still produce 32% – putting a lot more carbon into the atmosphere.
  • However, they also predict that 2005 was the peak year for US carbon emissions.
  • Renewable electricity generation will be a whopping 16% in 2040 including hydro (up from about 12% now)
  • Interestingly, biomass electricity is predicted to surpass hydro as the largest renewable form of energy production.
  • Solar is predicted to be 7.5% of the renewable mix (i.e. 1.2% of total energy production) in 2040.
  • Fully electric vehicles will account for about 1% of vehicles sold in 2040.

Of course, given how dirty our electricity will still be in this model (84% carbon or nuclear fuels), having an efficient gas engine will still be much cleaner than producing and transporting massive amounts of electricity for electric cars.

Beware the Carbon Bubble

Salon recently posted an article with a lot of great data about the ‘carbon bubble’, the carbon heavy fuel still available to be burned.

Basically, the value of the oil companies already includes all the fuel (oil, gas, coal) that they know of in the ground.  Oil company valuations only make sense if the stock markets assume that they will eventually extract and burn everything and it will be about as valuable as it is now on average.

Adding so much additional carbon in the atmosphere would have an overall effect on humanity somewhere between an economic depression and the extinction of the human race – no one is really sure.

I will go out on a limb and make the following predictions:

  • the price of oil will crash at some point in the next decade
  • a lot more carbon will be added to the atmosphere
  • climate change will be bad, but it will not end civilization

How bad things will get depends on how much green energy we can get online quickly.

Greenwashing WalMart

Here’s a great article with more info on WalMart’s moves toward becoming more environmentally friendly.  I’ve included some of the highlights below.

First off, WalMart is huge:

  • On average, 330 people checkout from WalMart each second.
  • WalMart is the largest private employer in the world with 2.1 million employees (the US federal government is by far the world’s largest employer in case you were wondering).
  • WalMart has 8,970 stores, 100,000+ suppliers, and as much as a 200 million metric ton carbon footprint.

They’re trying to be greener:

  • Truck efficiency is up 60%, plastic bag use is down 20%, and they had a 64% “waste-redirection” rate in 2010 (whatever that means. . .it probably means 64% of their waste was sold or given to other companies who might reuse or recycle some of it, probably lots of that is food).
  • Greenhouse gas emissions from their stores and distribution centers have been reduced by 20%

but there’s a long way to go:

  • Their stores use 27 BILLION kWh of electricity, so the 180 million kWh of wind power they buy is pretty small.
  • They have 130 stores with solar panels, but their stores cover more than 35 square miles of ground.  That’s bigger than Manhattan!

The more WalMart goes green, the better for everyone.  They are big enough that even the little things they do have a big effect.  Here’s the infographic from that Mother Jones article:

Source: Mother Jones

The Coal Phase Out

Here’s a video about Coal vs. Clean energy:

Something about this bothers me.  It seems to be gloating about coal’s demise, but prematurely.

According to the government, coal still accounts for about 42% of the enegry produced in the US.  Yes, it is declining (by about 6% per year) and solar (up 50%) and wind (up 27%) are increasing rapidly, but together they only account for a little over 3% of our energy production.

If these trends continue just as strongly as they are now, in 10 years solar and wind together will account for about 25% of our power production.  Coal will still account for about 23% of US energy production.

The big winner?  Natural gas, which accounts for about 25% of our energy now will grow to produce about 33% of our power. While much cleaner than coal, natural gas still produces fun things like carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxide, and harmful particulates.

So if things continue the way they are, coal will still be about equal to wind and solar combined in 10 years and natural gas will be a bit bigger then either – seems a bit premature to declare victory. . .

The Carbon Free Claims Of Electric Cars May Be Misleading

A recent article on Quartz claims that you can make a carbon free trip down the West coast in a Tesla Model S.  This electric car has a range of 200 miles and can be recharged for an additional 150 miles at one of Tesla’s Supercharging stations.  You just need to shell out $75K – $100K for the car.

The potentially misleading part is that the trip would be have no carbon footprint.  Even if the car produces no carbon, the production of electricity to power the car emits quite a bit of carbon.  The West coast, which has the cleanest electricity in the country, still creates much of its electricity from carbon heavy coal according to the Federal government.  28% of the electricity there comes from coal, 29% comes from natural gas, 22% comes from hydroelectric dams, and about 10% comes from all other renewables combined (the remainder is nuclear, oil, and other fuels including wood and flammable waste).

The rest of the country’s electricity is even dirtier.  Don’t listen to claims that electric devices are clean, because they are only as clean as the electricity they use!

The only way to have no carbon footprint would be to use only zero carbon renewable sources to produce the electricity that charges the car and I can find no claim that Telsa actually does this.

A columnist from Forbes agrees.

The point here is not to condemn electric cars, but to make our energy clean and to call people out on false or misleading statements.

Making Large-Scale Solar Cost Effective

A couple California start ups, Alion Energy and QBotix, are using robots to make utility scale solar much less expensive and faster to install.  Here’s the highlights:

1.  One robots lays concrete as the base for the panels instead of metal posts.

2.  Another robot comes along and assembles the panels, which are then wired manually.

3.  Once the system is operational, QBotix has a robot that will move along the panels and tilt them toward the sun, which increases production by around 40% and eliminates the need for motors built into the panels’ supports.

4.  The Alion robots can also move along the array of panels to clean them and remove vegetation that grows to shade the panels.  The robot is, of course, powered with solar energy from the panels.

All in all, these techniques sound like they could reduce both the upfront and operational costs of large-scale solar dramatically.  Read the full article from New York Times for more info.