Our one year experiment of living and driving on sunshine is over!

The idea is a simple one.

"Harvest endless sunshine from a small portion of a roof to provide 100% of the energy needed to power a home and the two cars in the garage, with zero utility cost, and zero gasoline cost."

On May 15th, 2015 we concluded our year long Driving to Net Zero Energy Challenge.  It's hard to believe that our two BMW i3's are already a year old and boy did time fly!  I'll have an overall wrap up post about the year on June 1st.

Before then,  I'll carve out a couple of sections and focus a little more in depth on various parts of the effort.

We believe we are the first household in the world to attempt this with full documentation.  We also believe that there are dozens, perhaps hundreds of other households who have accomplished the exact same thing without going though the painstaking detail and very public process of sharing private and personal information.

Thank you to BMWi, ChargePoint, Stellar Solar and SDG&E, for following us and supporting us during this past year.  It is because of a very efficient home, a great Solar PV system (installed in 2007) and the BMW i3's, the most efficient cars sold in the USA, that we were able to attempt this effort.

We have also documented this effort at every turn, with our utility, our Solar PV generation, and with the ChargePoint CT 4000 charging station in the greatest detail possible. With the ChargePoint CT 4000, we are able to account for every kWh taken from the wall and used for the BMW i3's.

Data is king,  ChargePoint with the CT 4000 and soon their residential home charger the ChargePoint Home, allows the owner to see data on each charging session in detail, just like checking up on your bank account or your friends on Facebook.

A focus on the BMW i3's powered by Solar PV. 

Our BMW i3's in the garage

We're loving our BMW i3's and they have been a joy to drive all year.  They have been trouble and maintenance free with the exception of one service visit for each car to update the software and replace the KLE.

The cars are a blast and spirited to drive, especially off the line,  and are very practical for our semi-urban lifestyle.  Every morning they await us with a full charge ready for the days adventure.  One detail in particular that has been very impressive is that we have no door dings, dents or scratches after a year of duty on the roads.  Typically for us we collect a few door dings and the occasional scratch every year.  The carbon fiber construction and thermo-plastic skin appear to be a great advance in not only lightweight construction, but also in durability and appearance.

Just one funny anecdote.  Of course we race our cars against each other! Julie and I both have the BMW i3 bev model, so we have to see who's got the fastest car.  In the first race Julie beat me by a long shot and  I was sure that BMW had made her car just a little faster than mine.  We swapped cars and did the same race again...and Julie beat me by a long shot.   I have concluded that my extra 150lbs was the difference in both races :)  Julie may be able to go 0-60 in 6.5 seconds, but it takes me a few ticks longer.

Using our stats we collected every month for the past year, here is in detail how our cars performed powered by Solar Energy. That's the beauty of the challenge. These are all actual and real world numbers, not estimates or calculations.
Location is Carlsbad Ca. 

• A total of 5061 kWh of electricity was used to drive 21,477 miles in two BMW i3’s.

• Julie averages 4.3  miles per kwh  11,862 miles / 2717kWh

• Peder averages 4.1 miles per kwh  9615 miles / 2344 kWh

• Our 8.5kw Solar PV system generated 13,546 kWh for the year. This equals 1593 kWh per kw system size

• A 3.18 kw Solar PV system (3.18 times 1593) would provide the 5061 kwh of power for both BMW i3s driven 21,477 miles.

• 37% of our overall solar generation was used by our BMW i3’s,  63% was used by our home

• It would cost $9540 to provide the solar supplied energy to drive both BMW i3's and subsequent cars, for 25 years (536,925 miles) 

• Two gas cars @25mpg (average fleet mpg) would use 859 gallons of gasoline to drive 21,477 miles

• Current cost of gasoline in San Diego Ca is $3.93 a gallon using 859 gallons of gasoline  is $3375

• The total cost of the PV System is equal to buying gasoline for 2.82 years.  An ROI of 35.4%

• Driving the BMW i3’s powered by Solar PV, the cost per mile is $0.017  cents per mile.  

• If advantageous TOU rates are factored in,  the Solar PV system size and cost would be reduced by 22%, the cost per mile would be $0.013 per mile.

• Driving on Solar PV supplied electricity is 1/10^th the cost of driving on gasoline.

Average price of gasoline on 5/22/15

You can live and drive on Sunshine :)

Cheers and thanks for reading and commenting.

Tesla Powerwall, Does it make sense?

We'll get to the math below soon, but allow me a couple of rambling paragraphs as prelude.

Did it make sense in 1983 to pay $10,000 in today's dollar (adjusted for inflation) for the first commercially available cell phone, the DynaTAC 8000, that had a talk time of 30 minutes, took 10 hours to charge and worked in less than 1% of the United States?  

Did this make logical sense when you could during the same timeframe, walk into a Sears, buy a corded telephone for $19 that worked all over the world and that cost much less per minute to use?

History answers that question for us with a world changing YES, going from one cellphone in 1983 to over 7 billion cellphones in 2015.  What was once so expensive and so exclusive, is now in the hands of everyone, by the way with battery energy storage that keeps on improving.

So too I am sure, one day in the not so distant future, battery energy storage will be the hands of everyone for their home and their cars. Remember this cellphone example when I do the math below.

Did Tesla invent battery energy storage?  No. Did Starbucks invent coffee? No.

 
Love them or not, Starbucks “reinvented” coffee and convinced us it was ok to pay $2.00-$5.00 for a cup of coffee…everywhere…several times a day.

Get ready to say Tesla Powerwall in Tall, Grande or Venti sizes soon as Tesla reinvents battery storage.

If you have been following our 12 month journey “The drive to Net Zero Energy”  you’ll know that our family lives in a home and drives two BMW i3’s with zero energy bills and zero gasoline cost all powered by Solar PV. 

Let's take look at our energy use and generation for last year. A year that ended with a $~450 energy credit to us.

If the premise is that you can take energy from the sun during day light hours and then store it to use during non daylight hours, the Tesla Powerwall is a huge money loser for most Solar PV users at the moment, due to "Net Energy Metering" agreements (NEM) and Time of Use (TOU) rates.   

California and many other other states have NEM agreements and TOU rates for solar PV system owners.  In fairness to Elon Musk, he pointed that out in his presentation with his comments about how in the near term, emergency back up is the best utilization of the Powerwall.

The NEM agreement, simply allows you to sell excess electric energy generation to the utilities generated during the day or longer summer months at the same price that you buy the energy from the utility at night or shorter winter months.   At the end of the year, if generation equals use, the bill is essentially zero. The NEM agreements last for at least 20 years.

TOU rates are two to three times higher during the peak hours (see chart above as we generate more during peak period) than they are during off peak hours.  Most of the large cities in California will have peak rates averaging $0.35 per kwh average of summer and winter rates, off peak $0.22 cents and super off peak $0.15 cents.  Essentially it's a 2-1 sale by using energy at night.

In our example, being grid tied to the utility, the result is no utility bill or gasoline cost.   Many argue both pro and con that other utility users are subsidizing solar PV customers, but I'll leave that for another day. Let's just say if I went off grid those same folks would say that utility users have to pay more since I'm not paying to be tied to the grid that comes to my home.  Sometimes you just can't win.

If I used a Tesla Powerwall to go "off-grid"  I would not get the financial arbitrage benefit of getting paid for excess generation during peak hours thus instead of an annual credit, I would have no utility bill but a large new expense for the Powerwall.

How much of an expense to go off grid?

I would estimate that our home and our two cars use an average of about 30kwh a day.   Roughly 10kwh for the 2 cars and 20kwh for the home.  Most off grid folks recommend 4 times the use to cover winter storms and the lower sunlight months of winter.

So lets assume a 100kw battery system for our home and cars.  It's just a guess since Tesla did not release the price for their larger units, but lets say the price is $30,000 ($300 per kw) and another $10,000 for installation for a total of $40,000.  

Assuming a high cycle life of 5000 partial cycles or about 12 years, I would need two of these systems during the 25 years of the Solar PV panels lifetime.  Again assuming a reduction in cost of half, 12 years from now and minimal installation expense as it's a swap out, the second system will cost me $20,000.

That's $60,000 for 25 years which equals $2400 per year for an off grid setup.   Grid tied I have a $~450 annual credit. So the math does not add up, but remember that first $3,500 cell phone and todays 7 billion cell phones as a strong lesson here.  Do you think the first cellphone purchasers cared about the economics of the cellular phone call?

So it begins with battery energy storage and the Powerwall.  Not yet a convincing financial equation for most homeowners with Solar PV, but a technology that is sure to to usher in the future.

As a solar PV homeowner and a multiple electric car driver, energy storage is the missing piece and I'm very excited to see Tesla and the Powerwall tackle this issue.  Energy storage will be a great enabler of renewable energy and our transition to electric zero emission transportation and cleaner air for our cities.

Today for the Powerwall,  last mile installations far away from power-lines,  new infrastructure projects without the needs for power-lines and utility scale energy storage make the most sense.

In the near term, "rate shaving" as high TOU rates creep into the darkness hours of early evening and we use the battery to cover that small time frame of dusk hours will begin to make sense.   In the long term it will make sense for all of us as prices fall and the technology advances.

There are other bright spots in addition to battery energy storage as well.  Our cars can each hold 20 kwh - 85kwh  of energy and vehicle to grid applications are developing to use that energy for the home or the grid.  New solar PV inverters come with a separate 15 amp, 1500 watt circuit that can deliver 7 to 10 kwh of electricity when the grid goes down each sunny day.  This is similar in quantity of electricity to the Powerwall.

In closing...when you use that cell phone of yours  to make your next call...remember how it got here and where it came from.

First communications, and now energy and transportation,  all three can be thought of as "internets" and they're all going to work together in the future to solve some of our worlds most vexing problems.

Bravo Elon Musk, Bravo Tesla and the Tesla Powerwall.

Cheers
Peder

BMW i8, 3 Months on the Road, An Owner’s Perspective.

Camping at Carlsbad State Beach

What this is not:  A journalist review, half a day in a car and then an impartial but “I need to make this interesting” review about the car and it’s relation to a competitive set of cars.

What this is:  An owner’s perspective after driving the car for three months and 4200 miles.   Emotions, experiences and life with our BMW i8.

Why the BMW i8?

Ever do a dinner at the French Laundry in Yountville? Noma, in Copenhagen?  Stay at a nice hotel in Venice or Paris?

The BMW i8 electrifies all the senses, similar to a world class dining or lodging experience. It does so, day after day after enjoyable day… As the extremely lightweight illuminated winged carbon fiber door is lifted, you know this car is something uniquely special,  your hands grip the wheel, the start button is pushed and you depart silently. A total package of luxury, enjoyment and experiences that is sensorially, viscerally, emotional every time a drive in the i8 is experienced. 

Each drive is looked forward to with anticipation, beginning as you first approach the BMW i8, and each drive is remembered when the car is safely back in the garage…even if the trip is to the local grocery store.

It’s an indulgence to own this car, but there is room in life for the indulgences, emotions and passions that when in balance with other life values, makes life so worth living. 

What the BMW i8 is not is a “thump on the chest, smoke the tires, cloud the air, vibrating, maniacal beast.”  No more so than the French Laundry is the place to get the 48 oz bone-in Rib Eye, with a "free t-shirt and free meal if you can eat it all” for $35.00.  

Staying a bit longer with the food meme… sure you can get more food at a lower price, no need for waiting or a reservation. However, crappy junk food sold to the masses (see McDonalds) is just not cutting it anymore in the marketplace.  The consumer is demanding something more. 

So too is the automobile consumer.

I’m torn between two futures for our BMW i8. 

On one hand our 2014 Electronaut Edition i8 “should” be kept as a low mileage garage queen as it’s future as a collectible is almost assured. Similar to the BMW M1 of the late 70’s that launched the M division, the 2014 BMW i8 is the flagship car that launched the I division.  I can imagine BMWi being as or more prominent in the future as BMW M is today.  It’s hard to predict the future and we usually get it wrong, but it’s equally as hard to imagine this car, and all that it represents not becoming a classic collectible.

On the other hand, the BMW i8 is a great car to drive every day and could easily be my daily driver racking up 10,000 miles a year for the next decade or two.  A car this beautiful and this capable should be driven until the wheels come off.   As far as cars in a similar class, it should be relatively easy and inexpensive to maintain the i8 with a three cylinder engine from the Mini and an electric motor.   

So which future is it, hard ridden worn out road warrior or a garage queen automotive artifact?  

To date we have taken the i8 on two long road trips totaling 3250 miles and an average of  300 additional miles a month driving the i8 around town.    I suspect this pattern will continue but I’m leaning towards driving the wheels off J

Driving Notes.

•  When on a long road trip and not plugging the car in, Our BMW i8 returns 32-35 mpg with a total driving range of around 350 miles.  Fill ups are around 10 gallons of gas.  It’s a great grand touring car with more than enough room for two people and gear.

• When at home driving around the city, our BMW i8 is getting 75mpg.

• Our BMW i8 can go 15 miles on electric only driving, 20 miles if I am hyper-mileing. Many but not all of our trips are electric only.

• All of the above numbers are very close to the EPA ratings.

• 4200 miles and not one glitch or visit to the service center, except for free car washes (thank you BMW of Vista)

• When at home we charge every time the car is in the garage. I imagine some drivers will seldom charge this car.

•  Our road trips were previously taken with a loaner car, as we are a two EV household.  Now the i8 replaces the loaner car on road trips.

• The i8 has a very wide dynamic range. From an easy, quiet going, super comfortable nice guy demeanor---to gear stick to the left position---Bad boy, racer boy, hooligan, damn that’s fast,  damn that’s loud, holy shit this an amazing car to drive.  Deep breath!  I’ve never experienced a car with both personalities before.  It’s part of the greatness of the i8, you can be a hooligan and then go full stealth mode.  Absolutely unique in the automotive world.

• The road devil is in that boy for sure.   I’m so going to be in trouble with the law; it’s just a matter of time.

•  If you’re an introvert or shy, you will have problems driving the i8.  When you open the doors of the i8, it’s like a 3300lb rare earth magnet attracting people.  Something about the i8 is extremely approachable and people are fascinated and inquisitive about the car.   It’s a bit much even for me and I’m hoping as more i8’s hit the road that this dulls out a bit.  My favorite line to date was from a six-year-old girl at a restaurant “Is that car from the future?”  My response was that the future was already here, would you like to sit in the car?  Her parents were overjoyed and took lots of pictures.   My practice has evolved whereby I don’t generally let stranger adults sit in the car but I do let children sit in the car.

• The i8 is a beautiful piece of industrial automotive artistry.

• When in sport mode, you can do 0-60 in less than four seconds, hit a governed 155 top speed, turn a 12 second quarter mile and the car has 357 horses and 420+lbs of torque combining both electric motors and the engine.  Many think that this performance can only be sustained for a run or two, or, a lap or two. Wrong.  When in sport mode the i8 is constantly making more electric energy than the electric motor can consume, hence full time all wheel drive.  As long as you’re in sport mode this goes on for hundreds of miles.    I’ve driven the i8 super hard in sport mode up a  22 mile twisty grade,  at the beginning, I had 6 miles of electric range, at the end I had 14 miles.   You simply cannot run out of juice for the electric motor when in sport mode no matter how hard you try. 

•  Speaking of sport mode, almost every drive involves at least a little of sport mode. It can be as brief as less than four seconds.

• When in comfort mode, which is similar to a traditional hybrid and the mode we use for long distance cruising, the cabin is extremely quiet and hard to detect engine noise except when passing, the ride is comfortable, not stiff and the steering wheel is light.

• When in sport mode, the car stiffens the steering gets heavier, the revs are maintained at a higher rpm and it can get real loud in the car.

• When in electric mode the i8 is perfectly capable in the city or on the highway, but slower than i3 0-60 with a top speed of 75mph.

• The i8 gets similar mileage and range in the city or on the highway.

•  I thought about buyer’s remorse a lot before buying the i8.  Would I get over the initial excitement and regret my purchase?  Although we can afford the i8, a purchase like this is very unusual for us.   So far no remorse, just the opposite, we are appreciating the car more than we thought we would.  It helps to know the car is retaining its resale value at or above the sticker price according to the 58 used i8 car postings on autotrader.com.

• We did not pay above sticker.  I am grateful to BMW of North America for making my purchase easy, and for their assistance with customizing the i8 with factory parts only available to Electronauts.

Thanks for reading, feel free to ask any q’s,  I’ll answer them as best I can.

Cheers!
Peder

Month 11, Harvesting America’s New “Gasoline”

Picture provided by Tom Moloughney.

Ubiquitous, equally available to all, zero emission, zero cost, powerful enough to provide the energy for all the cars in the country, and it will last forever.  The only question is…. 

Will you harvest it?

There’s a popular phrase that says,  “As goes California, so goes the rest of the nation” Perhaps a bit boastful, but in the automotive context; the pressures, regulations and trends, the forces that will shape the future of transportation in America, it rings absolutely true.

While most Americans only know of Solar PV as way to offset their home or business utility bill, Californian’s increasingly are becoming acutely aware that Solar PV’s highest and best use is as a transportation fuel.

Californians are harvesting sunshine to replace gasoline.

Solar PV is spreading faster than gasoline on fire...

According to the Center for Sustainable Energy and it’s last EV owners survey,  39% of California’s 125,000 plug in drivers (based on respondents to the survey) are making their own fuel on the rooftops and backyards of their homes with solar energy.   Surprisingly, the percentage of solar PV + EV combos over the years is growing not shrinking as more and more capable EV’s and PHEV’s come onto the market, and solar PV becomes more affordable and more attainable.  

With an electric car, you can make your own fuel. Try making and refining gasoline on your rooftop and let me know how that works for you. I'd love to see a picture.

Californian’s know that sunshine is a transportation fuel.

A fuel that when harvested is 1/10th the cost of gasoline, a fuel that when paired with an electric vehicle eliminates the largest source of emissions that American cities face.  In many cities, emissions from gasoline and diesel powered transportation contribute to over 50% of the man made pollution in that city. 

When a person in a city makes a decision to drive electric powered by renewable energy, each and every breath of air that we all share as a great “commons,” that we all inhale,  becomes cleaner for all, and health related issues of air quality are improved for all.  

Solar PV when used as a utility offset is good. Solar PV when used as transportation fuel is an enabler of financial savings and family wealth building due to tremendous gains in efficiency.

How, Why, What's the difference?

Solar PV when used to power the home, powers the same appliances, light fixtures and electronic devices that the utility supplied energy powers.  These appliances and devices are no more or less efficient whether powered by solar or utility supplied electricity.   Solar may be less expensive with zero emissions, but there is no inherent efficiency savings for the devices and appliances it powers.

Solar PV when powering a car enables an efficiency savings of between 300% and 400% as compared to gasoline powering a car.   Simply stated, a gasoline car will go 25 miles on average, and an electric car will go 100 miles on average using the same amount of energy.  Said another way, the electric motor is 3 to 4 times as efficient as a gasoline engine in converting energy to power the wheels.

In large measure because of these efficiency gains, the economic return of sunshine being harvested as a transportation fuel, is twice as great as when it is used as a utility offset to power a home or business. Even greater is the environmental benefits which are four times as great, as the emissions in our cities from our cars is four to five times greater  than the emissions from our homes.

It is for these reasons that Solar PV should be first and foremost thought of as a transportation fuel and secondarily as a utility offset for a home or business.  

Both are awesome, both are needed, but there can be no doubt that the greatest environmental benefit and the greatest financial savings are when solar PV is used to replace gasoline. 

As goes California, so goes the rest of the nation.  Bet on it.

We are demonstrating with this challenge that if you have an efficient home, efficient cars and solar PV, you can power your home and cars with sunshine zeroing out utility bills and gasoline bills.

As we progress forward, our experience and example becomes easier to do for others as solar becomes less expensive, efficiencies continue to improve, electric cars become better, less expensive and homes including the appliances, gizmos within, continue to become more efficient.  Energy storage via home and grid size batteries, on the near horizon, will also give a huge boost to solar and EV adoption rates.

We are just at a beginning.   But harvesting sunshine as a transportation fuel is spreading rapidly across America and it will not be stopped.  

Sunshine is America's new "gasoline."

May your days be filled with sunshine, onto the month 11 "Driving to Net Zero" energy challenge results. 

Our best month ever generating 235 more kwh's than we use.
Roughly 35% or our solar PV is used to power the cars, 65% to power the home.

We are now at 20,000 miles total of both BMW i3's, We have used
4.74 megawatts of electricity.  4.2 miles per kwh.

Imagine that your 2 car fuel cost and the cost of utilities for your home,
 could be below zero

We are already below zero in both cost and usage this year and the peak season
has not yet started.  The world leading efficiency of our two BMW i3's
are the main reason.

Next month will be the conclusion of our 12 month "Driving to Net Zero" energy challenge.  What an amazing year for us.

Thanks as always for reading and your comments.

Cheers!
Peder

(Past "Driving To Net Zero" articles)

• Energy Challenge Introductory Article

• Update Month 1

• Update Month 2

• Update Month 3
• Update Month 4
• Update Month 5
• Update Month 6
• Update Month 7
• Update Month 8
• Update Month 9
• Update Month 10