Electric vehicles (EVs), their emissions, and future viability

[turbobrick240]

Energy conservation and efficiency are definitely the place to start. Also referred to as negawatts.

 

[nicklockard]

Energy conservation and efficiency are definitely the place to start. Also referred to as negawatts.

Yes, exactly. Negawatts have a much faster ROI.

I had Solar City out to give a bid. Not surprisingly, they specified an under-performing system that makes them money but saves me little. A 20 year design life would net me less savings than the money that could be earned by putting the system's $140/month cost into an index fund. (It actually performed more poorly than a 3% earning fund.) I love solar and renewables (I work in the industry) but go*)(U(Uit, it needs to PAN OUT financially. I re-ran the analysis out to 30 years, and it was a little better than a 3% Schwab index fund, but not much.

Conversely, I saved a ton of money by just adjusting my programmable thermostat, judiciously watching peak power, decreasing pool pump run times, and the like.

Next I need to add insulation to the roof to bump up the R-value. Then add a temp-sensing garage vent to flush out the hot air when we park the cars. That will pay for itself super quick.

 

[bhtooefr]

Depends on where you're at. Here in SoCal, the PV additions to the grid have helped some, but almost made the situation worse. Most arrays are installed to maximize total generation in the day, but in this climate, that doesn't match the cooling demand. Peak sun is at solar noon, while peak cooling is more typically around 4pm. Some municipalities have started investigating the costs and benefits of incentivizing west facing arrays, which would more accurately mimic cooling loads.

I believe there's some places in Australia that are incentivizing west-facing or northwest-facing (due to being in the southern hemisphere) arrays, now, too?

 

[CraziFuzzy]

I believe there's some places in Australia that are incentivizing west-facing or northwest-facing (due to being in the southern hemisphere) arrays, now, too?

I wouldn't be surprised. When I said that south facing arrays was making the problem worse, it was correct - yes, they do offset energy usage, but that actually cause a higher rate of change in grid demand than no solar at all. With no PV, the load makes a gradual climb from about 9am, peaking out between 3 and 5pm, then gradual drop down to baseline by 10pm. Conversely, with south facing PV on the grid, load typically drops from 9-noon, then climbs much quicker between 1-3pm, peaking out around 5pm, then dropping down. Makes it much harder to track generation to that load profile.

 

[bhtooefr]

Of course, the best solution is likely south-facing with storage (both local and on-grid as necessary). That way, you get maximum energy collection, while being able to smooth demand (anything that's not needed to satisfy immediate demand goes into storage, and can be released later during the afternoon peak).

 

[Oilerlord]

Yes, exactly. Negawatts have a much faster ROI.

Not always.

We have 20 BR 40 floodlights in the soffits of our garage and around the house. Replacing them wasn't cheap ($18 each), and most of them aren't used very much. We could have replaced a few of them, but the difference in brightness and color temperature between new vs old would have looked strange; so we replaced them all. I get the argument that LEDs last 25 years, but our existing floods ran 13 years; we never had to replace any of them. I'm guessing most of them may have easily run another 13 years because they are only used occasionally - when a sensor turns them on when we turn into our driveway, or when someone walks up to the house. The existing bulbs were 75 watts each. The new ones are 15 watts. 60 watts of savings per bulb. With fees & taxes, our price per kWh is about 5 cents. Doing the math, burning an LED flood for 16.5 hours saves about 5 cents. We'd need to burn all of the bulbs for 5,940 hours to recover that investment. For us, it's not going to happen. Ever.

Same could be said inside the house. We replaced over 80 incandescents with LEDs at ~ $6.00 each. If we lit all of them for 12 hours per day, every day, the ROI could make sense. For us, that isn't the case. We only use ~16 of them on a regular basis.

(Solar) needs to PAN OUT financially. I re-ran the analysis out to 30 years, and it was a little better than a 3% Schwab index fund, but not much.

I'm sure for some, unless it pans out financially - solar is a non-starter. When we started our project, our ROI was based on 12 cents per kWh including fees & taxes, and I figured it would take 13-15 years. We're now at 5 cents. If electricity rates remain this low, I may not be in our house long enough to realize a ROI. Still, there's something magical about charging my car from the sun hitting our rooftop (like I am right now), or the solar powering our AC. Solar may not make financial sense, but what it does puts a smile on my face. That feeling more than makes up for our solar's financial shortcomings.

 

[CraziFuzzy]

Not always.

We have 20 BR 40 floodlights in the soffits of our garage and around the house. Replacing them wasn't cheap ($18 each), and most of them aren't used very much. We could have replaced a few of them, but the difference in brightness and color temperature between new vs old would have looked strange; so we replaced them all. I get the argument that LEDs last 25 years, but our existing floods ran 13 years; we never had to replace any of them. I'm guessing most of them may have easily run another 13 years because they are only used occasionally - when a sensor turns them on when we turn into our driveway, or when someone walks up to the house. The existing bulbs were 75 watts each. The new ones are 15 watts. 60 watts of savings per bulb. With fees & taxes, our price per kWh is about 5 cents. Doing the math, burning an LED flood for 16.5 hours saves about 5 cents. We'd need to burn all of the bulbs for 5,940 hours to recover that investment. For us, it's not going to happen. Ever.

Same could be said inside the house. We replaced over 80 incandescents with LEDs at ~ $6.00 each. If we lit all of them for 12 hours per day, every day, the ROI could make sense. For us, that isn't the case. We only use ~16 of them on a regular basis.



I'm sure for some, unless it pans out financially - solar is a non-starter. When we started our project, our ROI was based on 12 cents per kWh including fees & taxes, and I figured it would take 13-15 years. We're now at 5 cents. If electricity rates remain this low, I may not be in our house long enough to realize a ROI. Still, there's something magical about charging my car from the sun hitting our rooftop (like I am right now), or the solar powering our AC. Solar may not make financial sense, but what it does puts a smile on my face. That feeling more than makes up for our solar's financial shortcomings.

Keep in mind, however, that your $0.05/kWh is very atypical, so the ROI calculations for your of course are not going to look as favorable as to those who are spending upwards of $0.30/kWh.

regarding the 'happy factor' of solar. I'm very familiar with it. At my job, we installed a 1MW solar array on the roof of the parking structure, and the cost per kWh is a little higher than the very good commercial rate we pay to the utility, so the solar panels actually cost us a bit more. However, they also provide shade for the parking area, and are a positive marketing force as well, so I still consider it a net positive.
A similar decision process was made for my house, where I don't have much in the way of an appropriate roof for solar, but decided to self install panels as an awning over our patio. Not an idea array, with some shading problems, but I was going to build a patio cover there anyway, so might as well build it out of solar panels instead of roofing. Payoff for me for the relatively small array is something on the order of 6-8 years, depending on the production I actually get from it, and what electric rates do in that time. I may not even be here for that long, but I am enjoying the shade in the meantime, and it was a fun project.

 

[turbobrick240]

I wouldn't be surprised. When I said that south facing arrays was making the problem worse, it was correct - yes, they do offset energy usage, but that actually cause a higher rate of change in grid demand than no solar at all. With no PV, the load makes a gradual climb from about 9am, peaking out between 3 and 5pm, then gradual drop down to baseline by 10pm. Conversely, with south facing PV on the grid, load typically drops from 9-noon, then climbs much quicker between 1-3pm, peaking out around 5pm, then dropping down. Makes it much harder to track generation to that load profile.

In California yesterday the solar electrical supply peaked at 9900 megawatts @12:30 pm. At 3pm solar was still supplying 9600 megawatts. Demand peaked at 40,000 megawatts at 6 pm. Wind power generation peaked at 4200 megawatts at 5:45 pm. It looks to me like California could use more wind power generation along with more storage capacity.

 

[CraziFuzzy]

In California yesterday the solar electrical supply peaked at 9900 megawatts @12:30 pm. At 3pm solar was still supplying 9600 megawatts. Demand peaked at 40,000 megawatts at 6 pm. Wind power generation peaked at 4200 megawatts at 5:45 pm. It looks to me like California could use more wind power generation along with more storage capacity.

Those numbers are only for licensed wholesale solar facilities, I'm guessing, not the massive amounts of commercial and residential solar that is only typically metered as reductions in consumption. Most of those large solar farms have sun tracking, so they produce longer in to the afternoon than the fixed south facing arrays that make up the 'invisible' solar production.

 

[CraziFuzzy]

http://www.latimes.com/projects/la-fi-electricity-solar/

 

[VeeDubTDI]

http://www.latimes.com/projects/la-fi-electricity-solar/

Very interesting article. More workplace EV charging stations would help with the daytime solar surplus while simultaneously reducing the nighttime load.

 

[turbobrick240]

Those numbers are only for licensed wholesale solar facilities, I'm guessing, not the massive amounts of commercial and residential solar that is only typically metered as reductions in consumption. Most of those large solar farms have sun tracking, so they produce longer in to the afternoon than the fixed south facing arrays that make up the 'invisible' solar production.

I think you're right about those numbers being commercial solar. I would be surprised if the majority use sun tracking though. According to the article you linked, utility scale solar supplies 10% of the grid needs, and non-utility scale another 4%. California utilities were ill prepared for the explosive growth of solar and are still trying to add more fossil fuel capacity when they should really be adding storage capacity.

 

[CraziFuzzy]

In my area, all the actual commercial production facilities (whose sole purpose is to generate electricity, not cogeneration to offset consumption) use at least single axis sun tracking, most often the panels arranged in North-South rows that tilt to follow the East-West movement of the sun.

 

[nicklockard]

Keep in mind, however, that your $0.05/kWh is very atypical, so the ROI calculations for your of course are not going to look as favorable as to those who are spending upwards of $0.30/kWh.
regarding the 'happy factor' of solar. I'm very familiar with it. At my job, we installed a 1MW solar array on the roof of the parking structure, and the cost per kWh is a little higher than the very good commercial rate we pay to the utility, so the solar panels actually cost us a bit more. However, they also provide shade for the parking area, and are a positive marketing force as well, so I still consider it a net positive.
A similar decision process was made for my house, where I don't have much in the way of an appropriate roof for solar, but decided to self install panels as an awning over our patio. Not an idea array, with some shading problems, but I was going to build a patio cover there anyway, so might as well build it out of solar panels instead of roofing. Payoff for me for the relatively small array is something on the order of 6-8 years, depending on the production I actually get from it, and what electric rates do in that time. I may not even be here for that long, but I am enjoying the shade in the meantime, and it was a fun project.

You bring up a point I forgot to assess--shade benefit. I might re-run my analysis with the shading factor input. Hmmmm, the system Solar City specc'd would prevent xxxx thermal watts of solar thermal gain on roof from landing--requiring about 'y' tons less chilling to maintain constant temps.

 

[Oilerlord]

http://www.latimes.com/projects/la-fi-electricity-solar/

At times, California pays to give away excess power to Arizona...and that, with rooftop solar only at 4.2%. Very interesting indeed. Clearly a large-scale, managed storage solution will become necessary as the percentage increases.

It makes sense that the battery storage in EV's may be part of the solution, but isn't the solution.

 

[Oilerlord]

You bring up a point I forgot to assess--shade benefit. I might re-run my analysis with the shading factor input.

It definitely makes a difference. In my setup, 15 of my panels cover the WSW roof of my garage, and 19 are on the WSW roof and outside wall where our master bedroom is located. Both areas are noticeably cooler in full afternoon sun.

To an earlier point about orienting panels true south or west - west works for us (not that we had a much of a choice given our roof surfaces are fixed). Our AC is our biggest power consumer in summer; so it makes sense that our peak generation comes in around 4PM.

 

[VeeDubTDI]

Very interesting article. More workplace EV charging stations would help with the daytime solar surplus while simultaneously reducing the nighttime load.

I was thinking about this some more last night as I was zoned out, mowing the yard.

California would save money by installing workplace charging stations and giving that power away for free, compared to paying Arizona to take the power. It would also increase renewable utilization since Arizona is currently curtailing their own PV energy in order to use California's excess PV energy.

 

[turbobrick240]

You'd think they could find something more productive to do with excess generation than pay others to take it. Car charging, thermal storage, battery bank charging, hydrogen production, ...something.

 

[CraziFuzzy]

You'd think they could find something more productive to do with excess generation than pay others to take it. Car charging, thermal storage, battery bank charging, hydrogen production, ...something.

The sheer fact that they are doing it, sort of indicates that giving away the excess power is cheaper overall than shutting down a couple large baseload plants during the day.

Storage isn't really something that's going to work all that well for these type of short-term swings. Storage of the scale large enough for that comes down to pumping water between two different elevation lakes, which is something that takes some pretty extensive public works to achieve, and not something CA can really deal with when we don't have enough actual water reservoirs to begin with. To intentionally leave one empty just to buffer the power grid is not something that makes a whole lot of sense.

Battery storage makes sense on the small scale, at the point of use - not as a grid mechanic.

 

[CraziFuzzy]

Really, the long term solution is more aggressive demand response to loads that can be demand regulated. This is really the end-goal of the 'smart grid'. When cooling systems and EV charging can be short term regulated by the grid managers, the entire system can be smoothed out to where a couple baseload plants likely COULD be shutdown... or more accurately, no new plants would need to be built as population continues to grow. As we move to a more renewable driven grid, the generation can no longer follow the load, as it always has been - the load needs to learn to follow the generation. Luckily, we have all the tech to make that happen, just a matter of it getting out there - and it is. Just as the incentives increased the adoption of renewable sources, it is also increasing the adoption of demand response programs, in residential, commercial, and industrial segments.

 

[VeeDubTDI]

Hydrogen production, car charging and water desalination are all large-scale energy consumers that could be used to maximize the productivity of existing renewable generation. I don't think battery and thermal storage are there yet in terms of grid-level scale, but they probably will be someday.

 

[bhtooefr]

And hydrogen produced with RECs would likely fulfill the renewable mandate in California's hydrogen supply.

 

[Oilerlord]

Really, the long term solution is more aggressive demand response to loads that can be demand regulated. This is really the end-goal of the 'smart grid'. When cooling systems and EV charging can be short term regulated by the grid managers, the entire system can be smoothed out to where a couple baseload plants likely COULD be shutdown...

That's what happens in Alberta, plants are quickly taken on and offline as demand fluctuates.

http://ets.aeso.ca/

By the way, our 30-day average wholesale price for electricity is an incredibly low 1.694 cents per kWh. I'm on a spot pricing plan where I pay wholesale + 1 cent.

 

[turbobrick240]

Hydrogen production, car charging and water desalination are all large-scale energy consumers that could be used to maximize the productivity of existing renewable generation. I don't think battery and thermal storage are there yet in terms of grid-level scale, but they probably will be someday.

I think thermal storage may be getting close. Here's a good article in Scientific American:

http://www.scientificamerican.com/article/storing-heat-to-make-solar-electricity-all-the-time/

 

[Oilerlord]

I wouldn't mind storing the otherwise wasted heat from my solar panels. Cooler modules produce more power, and that waste heat could be directed to our hot water tank in kind of a hybrid solar / natural gas heating setup. Win-win.

Found this:

https://www.greenoptimistic.com/hybrid-solar-water-heater/#.WVQGfmjythE

 

[CraziFuzzy]

I think thermal storage may be getting close. Here's a good article in Scientific American:
http://www.scientificamerican.com/article/storing-heat-to-make-solar-electricity-all-the-time/

Storage at a solar-thermal plant is viable, as the article here discusses, and is used in a number of solar thermal plants being built (though they really only draw enough heat off the storage overnight to keep the steam plant up and running, not really producing much power at all). What we were discussing was storage as a means of leveling the grid out, where a plant would actually heat a substance when energy was available and then draw that heat off later when it wasn't - this is a very inefficient process with the current methods out there, and probably the least efficient form of grid storage. Thermal storage really only makes sense when the main process involves thermal energy to begin with (like the solar thermal plants, or building heating/cooling systems).

 

[turbobrick240]

Storage at a solar-thermal plant is viable, as the article here discusses, and is used in a number of solar thermal plants being built (though they really only draw enough heat off the storage overnight to keep the steam plant up and running, not really producing much power at all). What we were discussing was storage as a means of leveling the grid out, where a plant would actually heat a substance when energy was available and then draw that heat off later when it wasn't - this is a very inefficient process with the current methods out there, and probably the least efficient form of grid storage. Thermal storage really only makes sense when the main process involves thermal energy to begin with (like the solar thermal plants, or building heating/cooling systems).

Correct, the idea behind thermal storage is to store excess energy for later use. The article discusses thermal storage as a means to level grid supply. The author mentions storing the energy from photovoltaics, wind turbines, and concentrating solar thermal in molten salts, and ceramics. Other articles I've read also include silicon, concrete, and phase change materials for storing heat. That heat can then spin a steam turbine, power thermophotovoltaics, or be used for industrial applications requiring heat.
While the efficiency takes a hit every time energy is converted from one form to another, paying to get rid of that excess electricity isn't terribly efficient either. A typical PV panel may only be 16% efficient, but sunlight is free.

 

[VeeDubTDI]

A typical PV panel may only be 16% efficient, but sunlight is free.

Interestingly, I met a gentleman at our local EV club meeting who is a Sunpower installer and he mentioned that their PV panels are up to 23% efficient right now. Pretty good advances have been made in recent years.

 

[turbobrick240]

Interestingly, I met a gentleman at our local EV club meeting who is a Sunpower installer and he mentioned that their PV panels are up to 23% efficient right now. Pretty good advances have been made in recent years.

That is fantastic. It looks like Panasonic is breathing down their neck for the most efficient panel title. At one point the big competition was between Sunpower and LG. I guess LG is focusing more on less costly panels now. They still make some of the best panels though.

 

[kjclow]

@Oilerlord, it's working well so far. I purchased the two anmeter version because it improves error correction down to <1% precision.

I've walked around turning various devices on and off, and after a time delay of about 3 update cycles (I have mine set to report every 10 seconds the power consumption), it displays accurately. The handheld station seems to display time-averaged power so people don't freak out at every little thing. I can see as little as an 8 watt load from switching my Bosch dish washer in on/standby mode. My ceiling fans consume surprisingly high wattage too.

Having this motivated me to switch out all of our daily-use incandescents to dimmable LED bulbs. This both lowered the power consumption directly and indirectly also since they don't generate nearly as much waste heat that the AC then has to remove. I calculate that I've removed 1700 watts of waste heating by making this switch.

You should also look at replacing your ceiling fans with DC motors. Supposed to be more energy efficient and much quieter. I put one in my bedroom earlier this year and at a medium level you don't hear the fan or the blades. On high, there are 6 speeds, the thing will blow you out of bed but still can't hear the motor. In the fall, I'll be replacing the one in the living room with a DC motor too.