PaulRivers

We're getting into being a bit pendantic. I said "if you didn't bike would you need to pay to join a health club?" as a question some people consider, not as a universal rule for everyone. Some people might be jogging otherwise, others wouldn't.

I agree on some sort of other exercise, though there's a lot of other choices than weight lifting or running. I quick search suggests baseball, basketball, or exercise videos like Insanity where jump around at home a lot. I personally started doing kickboxing for more of a balanced upper body workout (the fitness kind with a bag, not hitting people).

T Stew

I thought we were just being a little silly. Surely one wouldn't consider the cost of charging some batteries to that of ones life long health. I mean probably every other cycling related expense (tires, tubes, handlebar tape, waterbottles, helmet, etc) cost more than charging batteries. And you can continue to cycle even without charging batteries at all.

southpawboston

I am still grid-tied, but in the next few years the prospects of off the grid power will be very realizable, with technologies like the Tesla power wall battery storage system becoming reasonably affordable. I'm on the waitlist for a Tesla power wall, but this first generation are really only good enough for backup purposes. I couldn't power my house over the course of a whole night with one. But they are really useful for short-term outages. If I end up building my tiny rural getaway cabin, solar + power wall is how I will go.

Road Fan

Interesting!

Is the Power Wall designed to be paralleled to achieve overnight capacity?

Do you have frequent short outages in civilized Somerville?

I stayed on the edge of S. on a business trip to MIT, and the power was nice and stable even with the cold, ice, and rainstorms.

T Stew

I;m still unsure if this is a troll thread since it sounds so ridiculous but I should also acknowledge that the price of electricity here is about as cheap as it gets and I know it costs much more in other areas. I don't know how high it gets in other parts of the world too, so perhaps it does mean something to some people.

The cost here is in the cents, I think around 7-9 cents a kWh? (and charging a battery consuming probably 1% or less of a kWh depending on the battery). That isn't including the fixed fees and other charges though... you pay a per kWh rate for the energy plus other fees and charges, and in my case since my electric usage is fairly steady if I simply divide my total kWh usage by my total bill lately over the last 6 months I've averaged 573kwh/month and paid total bill avg of $90 so about $.15 per kWh including all fees. Just realize when you include all fees its not linear with usage.

Very cool. As you can see my rates are pretty cheap already and I figure that means what I would get paid for grid-tied solar wouldn't be as much either, so that's why no one around here has done it yet. But if I was up in New England where rates are double then maybe. The problem I have is right now like 50% of my bill is fixed fees. I had one month I wasn't here but one week and still had like $50 in fees and only like $15 usage (fridge, freezer, and hot water heater - forgot I could turn that off, were the only things running). If I built a house 1/4 mile up a wooded hillside or something, I might have to pay $10,000-$25,000 to run power to it. Then putting in solar makes more sense, avoiding the huge hook up fees, and no more monthly fixed fees that are regardless of how little I use. I can reduce my usage even further with gas water heater, gas oven and range, etc. With a stand by gas generator ready for the days when the sun isn't shining enough. I haven't really looked into the cost of batteries though, I know off grid with batteries is much more costly compared to grid tied with no storage. If I were in a house that was already grid tied, and perhaps with less monthly fees then going grid tied makes a lot more sense. My current house I want to move from, its too big an inefficient, and not enough land, so this is all based on where I move in the future and I really have no idea where that will be but I really would like to move to near the Adirondack Mountains in NYS, perhaps on the southern edge where Albany is still within driving distance.

Mr IGH

I'll take a SWAG at it.

Assumptions:
A large charger will be rated at 100W.
It takes about 3 hours to fully charge the battery.
Rider charges battery pack every day for 3 hours.

Cost:
Based on the above assumptions, every charging session is .3 KWatt*hour (KWH). A KWH cost between $0.08~$0.33 in the USA, average is $0.12.
Each charging session cost between $0.024 and $0.11. Even if rider charges battery every day the cost of charging will be $8.76 and $40 with an average of ~$13 in the USA.

This is intentionally weighted higher than expected by using a 100W charger for 3 hours, more accurate is ~50W for ~1hour which is about 0.050 KWH per charging session. With a cost of $0.12 per KWH the annual cost of battery charging for 200 days would be ~$1.20 for the year....

Dyno lights have never been about saving money. My bike isn't overly expensive by my standards (~$1500 with the extra wheelset) but some folks think I'm nutz.

T Stew

I think your weighted way to high... unless your using 10,000 lumen headlight & tailights every day!

People use varying amount of lights, depending on the quality of light they have or ambient lighting (sometimes you just need a light to be seen, so not as bright).

It takes a lot of testing and measurement to figure this out accurately, much more than I am willing to do. You can't really guess that your charger is 100W and guess how much you use in a week, you need more firm numbers. Lets start with actual light output and go back from there. Fortunately both the lights I use and batteries have been tested on the net, so some of the work is done for me..

I can easily get by with my 1,000 lumen headlight turned down to 330 lumens in the dark country (when on my single AA light its 250l and that is good enough in a pinch, certainly good enough 'to be seen'). I sometimes ride with more, but the two highest modes are PID controlled based on temperature so runtime varies and results meaningless. But the 330 Lm mode is current regulated, measurable, and with my pretty industry standard Panasonic 18650 li-ion cell (3400mAh) it lasts about 4 hours. This puts an amp draw slightly less than an amp on the battery, which has shown a total battery capacity for that range discharge of about 11.5Whr so with about 4 hr runtime that is about 3 watts per hour of usage. Now what is the efficiency of the charger and battery to take a charge? Results vary from 99% efficient down to 80%, and I can't find anything solid for my charger. To give maximum margin of error I'll say charging is 75% efficient. So that 3W per hour of illumination because 3.75W consumed.

So using Mr IGH's assumption of $.12/kWhr USA average rate, then for every hour you use 3.75W it will cost you $0.00045
You just need to then convert from 1hr to whatever you need... week or month, and adjust based on the brightness and efficiency of you headlight/batter/charger.

For example if I did 30 min 2x per day 5 days a week that is 5hrs total and $0.00225 per week. Or $0.00675 if I crank it up to 1,000 Lm for the same length of time for 1 week.

A big variable is how efficient the charger is, and this information isn't all that common. I don't have one but if someone had one of the kill-a-watt devices you could measure the total consumption to charger you battery, and then note how long the battery lasts for your usage. That would be the best way to really tell, better than all this guessing.