Category Archives: Energy

Electric Vehicle Efficiency

According to the U.S. government:

Energy efficient. EVs convert over 77% of the electrical energy from the grid to power at the wheels. Conventional gasoline vehicles only convert about 12%–30% of the energy stored in gasoline to power at the wheels.

Source: All-Electric Vehicles

Of course, one must also include the conversion of the original fuel source into electricity but that depends on the original fuel source: oil, natural gas, coal, nuclear power, hydro, geothermal, solar, wind and so on – and can vary widely.

Regardless, gasoline engines are not very energy efficient in terms of turning the energy in the fuel into forward motion, as noted above and also noted here. EVs have a slightly different problem – while they use electricity efficiently, EVs weigh quite a bit more than a similar sized gasoline vehicle.

Energy: Utilities experiment with automatically adjusting your thermostat to throttle demand

Utility companies want to be able to make the demand go up and down just as much as the supply fluctuates.

Source: How utility companies lower electricity use by controlling your thermostat | kgw.com

This concept works with “smart” thermostats. When electricity demand is high, such as during a hot summer day, the utility can remotely adjust your thermostat’s air conditioning settings to raise the interior temperature setting by a degree or two – thereby reducing power demand.

Individuals can still reset it back down, if they wish.

The power utility has also experimented with a voluntary system where consumers without smart thermostats subscribe to email or text alerts asking them to adjust their electricity usage.

Electricity has to be created, in real time, as it is demanded by customers. Traditionally, this meant coal and natural gas fired production plants which can ramp up and down quickly (hydro dams are not adjustable in real time). In the new model, the power companies are looking at altering the demand – not just the supply – in real time.

Transportation: Congress proposing an annual Federal tax on electric vehicles

Source: Congress could make EV drivers pay – POLITICO

My state, Oregon, introduced state fees for fuel efficient vehicles, beginning January 1, 2020. These fees are added to existing annual license fees. Oregon issues vehicle licenses for a 2 year period, not one, so the fee paid when renewing is twice the value shown:

a) For vehicles that have a rating of 0-19 MPG, $18.

(b) For vehicles that have a rating of 20-39 MPG, $23.

(c) For vehicles that have a rating of 40 MPG or greater, $33.

(d) For electric vehicles, $110.

The reason they charge for 2 years is it enables the state to increase the effective rate. On average, people will sell their car with one year of their license remaining. However, when sold, there is no refund. And presumably you buy a new vehicle and pay a new license fee. Same thing if you move out of state – you lose the unused portion of the fee. Now they offer a 4-year pre-paid option – don’t go there!

Oregon has also introduced a “pay per mile” license tax and says that some people may pay less fees under this scheme. When I checked the numbers for my Honda Fit, I would pay more under their pay-per-mile scheme – and I only drive about 7,000 miles per year. Sure, that pay–per-mile fee makes sense – not!

The state increased the regular vehicle license fee by 30% in 2017, and increased the state’s gasoline sales tax, which will increase every other year through 2024. The State also increased the title records fee and added a per-vehicle-sold tax on car dealers, and added a $15 tax on new bicycle purchases.

The proposed Federal tax – amount unknown – would be in addition to State license fees.

Transportation: Congress members introduce bill to establish a government run EV charging network

Reps. Alexandria Ocasio-Cortez (D-N.Y.) and Andy Levin (D-Mich.) on Thursday outlined a bill that seeks to establish a nationwide electric vehicle charging network within five years.

Source: Ocasio-Cortez, Levin eye national EV network in five years | TheHill

They admit they have no idea what it would cost taxpayers, where charging stations would be located, and would have the government establish charging standards (versus industry standards) … they have no details on anything because details don’t matter.  They do not even have a reason as to why the government needs to run this – apparently they have not heard of PlugShare.

How did we get by without a government run network of gas stations and restaurants along the Interstates? Boggles the mind. Worse, when the government runs the EV network and decides where EV charging stations will be located – watch out  for graft and corruption as politically favored communities get this infrastructure and less favored communities are cut off.

This bill will go nowhere (pun intended).

Transportation: How EVs are more efficient than ICE vehicles – power on demand and regeneration

ICE vehicle engines, except in hybrids and PHEVs, run all the time.

In an EV, you only consume power when you need power. This makes an EV ideal for city driving. When you stop at a traffic signal, your engine stops.

When you brake in an ICE vehicle, your engine keeps running as your forward momentum is converted into heat by the brakes. This means you consume fuel all the time and the kinetic energy is basically thrown away (by turning it into heat instead of future forward motion).

In an EV, when you brake, you are generating electricity. Essentially all EVs have regenerative braking capabilities. Your kinetic energy is stored for future use.

When you climb a hill or mountain pass in an ICE vehicle, once you get to the top, you can coast downhill, but the engine is still running at idle, at a minimum. Your potential energy is translated, partially (not 100% efficient of course), into kinetic energy of forward motion – but chances are that you’ll either use braking (converting kinetic energy into wasted heat) or engine braking (similar).

In an EV, once you have climbed to the top, your vehicle generates electricity on the downhill side, adding miles back into the battery pack. This converts your potential energy back into future forward miles.

As we note below, EVs weigh much more than ICE vehicles. Consequently it takes more energy to lift them up mountain passes, but with the ability to recover some of that energy on the way back down.

Transportation: The large dead weight of EV batteries

The 2020 Honda Fit (using ICE) and the 2020 Chevy Bolt (EV) are nearly identical in capacity and general specifications – except for one very notable item:

2020 Honda Fit – image from Honda web site

2020 Chevy Bolt EV – image from Chevrolet web site:

The two cars are amazing similar with nearly identical cargo space, with or without the back seats up or down. The Fit includes a spare tire, the Chevy Bolt does not.

The biggest difference – the price and weight of the vehicles.

  • The 2020 Honda Fit starts at about $16,000 and weighs 2,522 to 2,648 pounds depending on options and version.
  • The 2020 Chevy Bolt EV starts at $37,000 and weights 3,563 pounds.
  • A Tesla Model 3 weighs over 4,000 pounds.

The Bolt EV weights almost 1,000 pounds or 38% more than the Honda Fit.

Why? The battery. The energy density of EV batteries is very low relative to gasoline. EV makers have to use large batteries to achieve a range of 200 to 300 or more miles.

When we consider the overall energy efficiency and emissions of the two vehicles, we should note the inefficiency of carrying nearly 40% more weight for a small reduction in lifetime emissions:

Update: I wonder what impact the heavier weight of EVs has on roadway surfaces? Weight has long been considered a major factor in the degradation of roadway surfaces. If we transitioned the entire automotive fleet to vehicles weighing 30-40% more, what effect does that have on roadways and what are the costs associated with those effects?

Continue reading Transportation: The large dead weight of EV batteries

Energy: Global prices for electricity

Page down the chart – prices range from 1 cent to 41 cents per kilowatt hour.

Source: Electricity prices, June 2019 | GlobalPetrolPrices.com

The U.S. has an average price of 15 c/KWH. Where I live its about 10 c/KWH but there is a separate monthly charge for the power company’s infrastructure including distribution networks. That makes sense because when you have solar PV net metering (like us), we pay for the distribution network in the fixed part of the monthly fee, and they pay us for excess power production and we pay them when we do not produce enough.

Lower costs, presumably, make access to electric vehicles more compelling.

Climate: Tried using the EPA Household Carbon Emissions Calculator and its a Fail on first Question

The first question on the EPA Household Carbon Emissions calculator is to select my type of household heating:

  1.  Natural Gas
  2. Electricity
  3. Fuel Oil
  4. Propane

We heat our home with locally produced wood pellets. Since I cannot answer the first question correctly, the entire calculator fails.

I used this one at the University of California, Berkeley and it estimates our household annual carbon emissions at about 20 tons of CO2e per year, or 62% less than the average  American home.

I used a different one in the past (link not saved) and it estimated our usage at around 16 -17 tons, and said the average home was about 40 tons/year, which seems inline with the UCB calculator.

Transportation: Do electric fire trucks make sense today?

Electrified fire trucks:

It can drive for up to 30 minutes on pure electric power, with a diesel generator for backup power.

Source: Fire Truck – Electric Fire Truck – Electric Vehicles

On the plus side, most fire trucks travel limited distances from their station to an emergency scene (by design) making them ideal for EV platforms with limited range. Of course they occasionally travel longer distances for out of district support and training.

During a fire, the truck must also power large water pumps. However, the majority of fire engine responses are not for fighting fires. When I was a volunteer firefighter, about 2% of calls were for fires, about 10%+ for vehicle accidents, and almost 90% for medical aid. Each department will have different ratios, of course.

On the negative side, the typical city fire truck averages about 5,000 miles per year:  converting to EV platforms has little impact on overall CO2 emissions compared to other options. They just don’t drive very far (by design!). By comparison, a typical large diesel semi truck used in transportation travels almost 70,000 miles per year.  Which EV conversion would have a larger impact on CO2 emissions?

(Click on image for larger view)

New ICE fire trucks appear to now cost about $500,000 and up; prices have risen rapidly in recent years due to new  safety requirements from the NFPA and that new trucks are generally larger than the vehicles they are replacing. Paying $1 million and more for a fire truck has become routine –  which seems pretty obscene but no one bats an eye because public safety.