One Finite Planet

Home Charging: The Challenge To A Green Equitable EV Transition

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Moving to EVs is going to increase electricity requirements, and at a time when there is already a technical challenge to more the electricity supply to "green" source. But what it electric vehicles could solve the "green power grid" problem, provide energy security, and avert a threat of increasing inequality? It turns out dream scenario is definitely possible, but can be fully realised only if the home charging problem be solved.

The Dream.

Imagine a world where all the cars are electric, and when at home, all are connected to the grid. Australia has 16 million cars, the USA has over 275 million. If all these vehicles became electric and the batteries could be connected to the grid, this would represent 1 terra watt hours of storage in Australia, and in the USA, 20 Terra Watt hours (20,000 GWh). To put that is perspective, as search for “worlds largest battery” found the just over 1,000 MWh (1 GWh) battery in Texas. A fully electric car fleet in the USA would provide almost 20,000 times as much storage as this current worlds largest battery, without assuming car batteries . If the US had access to just 10% of that storage, it would be equivalent to 2,000 of the worlds largest batteries, distributed around the USA. For perspective, the largest battery is equivalent to equivalent to around 10 thousand F105 lighting (the electric version of the top selling vehicle in the US), and Ford has over 200,000 orders for the 150 lighting.

The largest battery announced for Australia to be built over the next few years is currently the 0.7 GWh battery for Eraring, over 1,000 times less than the storage to be expected if Australia’s cars all were to become electric.

Note that these estimates are on current car battery sizes, and car battery capacity continues to rise as the price per kwh drops, so by the time almost all cars are electric the storage will almost certainly be even greater.

Making The Dream Real Or The Nightmare.

Cars Could Act As Batteries for the grid.

Cars spend 95% of their time parked and 4% being driven.

This first factor enabling batteries to have significant time available to the grid, is that while cars are purchased for their ability to be driven, they spend almost all of the time parked, and 90% of the time they are, parked is at home or at work. If people have a connection to the grid at home and at work, then it would be feasible to have cars connected to the grid on average around 85% of the time.

People rarely do road trips, which is the only time EVs require their full battery capacity.

The second factor is that much of battery capacity of EVs is required only when on “road trips”, and on average, people spend less than 4 weeks per year on road trips.

During typical days with only local trips, people very rarely travel over 100km (60 miles) in a day, and with an EV that has home charging, that power is put back each night.

This follows from experience of people with gasoline/petrol vehicles, which normally spend several days between needing refuelling, except on road trips, when they may even need refuelling more than once a day. In fact, refuelling around once a week is for most people sufficient for commuting.

EVs can be charged every night even if they do not needed , which changes the difference between “road trip” and “not on road trip” from how many days between refuelling a gasoline/petrol vehicle, to how much battery has been used between the daily recharges with an EV.

Unless there is some form of national emergency, no one would want to give back all of the charge of their electric vehicle back into the grid, but providing around 15% of a vehicles range, would normally be practical for almost everyone. All vehicles except those on a road trip, or about to go on a road trip, or just being driven at the time, could provide around 15% of their power on demand. This 15% of charge from the available cars would be sufficient to make the target of around 10% of the battery capacity of all electric vehicles available to the the grid. This is enough as enabler to allow solar and wind for a dream transition to renewables.

Nightmare: Planned Charging Networks Are Not Appropriate Infrastructure.

Public Charging Stations Are Not Appropriate Charging Infrastructure.

Typically, charging for electric vehicles is seen as a matter of proving charging stations that replace existing replace fossil fuel stations, despite all evidence that most electric vehicle owners recharge almost exclusively at home, unless on a road trip.

Appropriate charging infrastructure is home and/or office charging for people for when they are not on a road trip.

I saw one article I will find the link to quoted 35% of Americans do not have access to charging at home. I find this statistic suspiciously low, and may not account for those who do have access to charging at home, but must share the one charging location between several vehicles. I certainly know that one the streets around my home, there are always a large number of cars parked on the street. Some homes have one off street car space, but as many as 3 or even 4 cars to the household. There are also areas within my city where almost no homes have any off street parking. Combine this with the large number of apartment dwellers without a power socket at their car space, and the numbers increase further.

Many governments seem to see the solution to EV charging for those without access to home charging as commercial charging stations. While these stations are needed for road trips and for emergencies, they are not an appropriate solution for home charging because:

  1. They are socially inequitable for home charging.
  2. The do not allow cars to form part of the power grid.

Socially equality: Should Lower Income Households Pay More for Vehicle Fuel?

Operators of charging stations must buy electricity, pay rent or ownership costs on their land and infrastructure, as well as maintenance costs. It would be unreasonable to expect them to sell electricity as the same rate people pay for their home electricity.

But then those who can charge at home, are paying home electrical prices when not on a road trip, while those who cannot charge at home, can be paying far more. Less affluent people are less likely to have the ability to charge off street at home. Is an increase in the divide on the basis of wealth what we desire?

Yes, there are some public free chargers, but “there is no such thing a a free lunch” dictates these will not necessarily stay that way. If you can charge at home, then it is your choice to do so or not, while if you have no choice, you have to pay the price of what is available.

There is a further price. Rapid charging reduces battery life, and will therefore increase mainetenance and ownership costs beyond just the cost of electricity.

Unless this charging at home problem is addressed, yet another step of social inequality is about to be added.

Rapid Charging Does Not Provide The Connection To The Grid When Parked.

The entire “substantial reduction to the cost of national infrastructure” proposal is lost if cars cannot be connected to the grid. Nationally, there is a significant budget available to solve this problem. Further, there is a huge windfall for the environment from solving this problem, but are we motivated.

Large Scale Rapid Charging Quadruples The Need For Batteries.

People unfamiliar with EVs, assume the solution for people without home charging is for these people to replicate the internal combustion engine vehicle experience, and refuel at a public refuelling station that is the equivalent of a “gas station”. But the costs over and above refuelling at home at not just limited to the costs born by the owners of these cars.

Consider the factors that increase battery requirements:

  • Cars that are not connected to the grid increase the requirement for battery storage in the grid.
  • The batteries in cars always charged by rapid charging deteriorate faster and require replacement.
  • EV charging stations have huge peak electric current requirements, which can only be met installing additional batteries at the charging stations.

The Costs Go Beyond Batteries.

With less distributed batteries to smooth handling peak loads, the grid may requires upgrades the grid would require upgrades in neighbourhoods with insufficient “home charging”, or more specifically home connected to the grid cars., as heating and other appliances all move to electrical.

Then there are the charging stations themselves, which in urban areas, require expensive real estate in addition to the charging infrastructure. EVs also currently require more frequent charging than gas cars do refuelling, and spend longer recharging than gas cars do refuelling.

Implementing A Solution.

Politics.

When the power grid was introduced to most countries, it was seen a national infrastructure to be shared by all. Pricing was not specifically user pays, but was designed around ensuring an economically viable system. As one the earliest adopters, the US began before regulation was introduced to rationalise and the system and ensure fair pricing without the need for replication of the infrastructure. and prevent The same principle applied for the telephone system. Each was seen as essential infrastructure. This principle of regulation to ensure fair pricing without the need for multiples of the infrastructure enjoyed less support with the internet infrastructure, and with mobile phone networks, but could be needed again for an optimum solution for EVs and the upgrade to electrical infrastructure.

A country that does treat the completely revised power system as a national project and tackles the infrastructure requirements, will be at a competitive advantage compared to countries that do not. However, economic activity increases when costs to consumers are higher, and lucrative markets do generate corporate profits, so the politics will be complex.

Economics And Energy Security.

Import Reduction and Energy Security.

The economics is not simple, but once the national economic and security cost of importing fossil fuel is considered, the case becomes compelling. For both example countries, the USA and Australia, Oil and Gas is a major import, add as high as around 10% of total imports for the USA, and given there are no offsetting exports as with other imports, an even higher percentage of the trade deficit.

Plus Russia’s actions in the Ukraine have demonstrated the vulnerability of the national market to foreign factors, and brought energy security, and national security to the forefront. Another key point made by Dennis Blair, a retired naval officer who served his country as commander in chief of the US Pacific Command, is that the raw material for batteries become critical to energy security in the future. Following a path that applies aa perhaps 4x multiplier to a country’s battery needs, is not the path to security, or financial success.

In Australia, the economic equation is even more compelling as there is basically no local “oil”. Perhaps the best placed country in the world for renewable energy, Australia is almost totally dependant on imports for its transport fuel requirements.

To get where a country needs to be, all road vehicles need to be electric, and all power sustainable. This requires either a significantly entire upgraded grid, or a network of both battery storage and peak load buffering, in addition to provision for charging electric vehicles. Or, the charging infrastructure for charing electric vehicles can provide the battery and buffering, all at once reducing the total investment required.

The Maximum Economic Activity Option.

There is more economic activity if the current path continues. Ensuring car batteries fail earlier could in the long term, result in more car sales. Forcing those without home charging to buy premium electricity through an intermediary, will generate profits for the intermediaries. Perhaps even sufficient profits to fund more lobbyist and political donations. The additional expense of additional batteries required to compensate for EV batteries not being connected to the grid will raise the cost the electrical network, and force higher power prices, which again means more economic activity. But unproductive economic activity damages national competitiveness, and increases the disillusionment of the public who see the economic activity indicators and corporate profit rise, but feel their own circumstances eroded.

What Is Needed To Make It work?

Mostly vision and planning, with some new legislation on the role and obligations of power utilities. Clearly, big oil will fight this, as it could acceleration the move away from fossil fuels. What is really needed is someone to champion the need. Tesla does not seem likely play that role in the US, and finding those motivated in other countries will be quite a challenge. In this day and age, finding those who wish to limit the potential for profits from lower income groups may not be easy.

The Technology Requirements.

Vehicle To Load, Home and Grid Are All Possible, But Currently Rare.

Vehicle to load is the ability for a car to use its battery to supply “mains” electricity to power appliances.

Vehicle to home is the ability to power a home’s switchboard from a vehicle, those providing “whole of home”” power in the event of a power disruption.

Vehicle to grid is the ability to feed the power from the car not just to the home, but to the electrical grid, allowing the entire grid to be powered from vehicles, if there are sufficient vehicles connected to the grid to make a meaningful contribution.

So far, the most common is the simpler “vehicle to load”, as provided by the latest Hyundai, Kia and Genesis vehicles, as well as some vehicle in the Chinese market. The ford F150 Lightning promises vehicle to home. A barrier is that current charging systems were designed long before batteries had sufficient energy for these ideas to be realistic, and support in current charing standards is currently still be added.

Adopting A Wireless Charging Standard.

The world is a little of a tower of babel with regards to wired charging system standards. The US has 3 different systems. The good news is there seems to be a single wireless charging standard emerging, and being a more recent design, the standard already supports vehicle to grid. Wireless charging can be more efficient than by cable, and it not too late to declare a national wireless charging standard, together with a date from which compliance will be mandatory. For the purposes of home charging, or power to the grid, peak power delivery requirements are significantly lower than rapid charging requirements, so compliance would not be onerous.

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