feeding your phone m&ms

Many of us who had long term (over a week) power outages during superstorm Sandy and the Nor'easter that followed ran out of batteries, candles, lacked electricity to run natural gas furnace fans, had problems charging phones and laptops, lost refrigerated food and ate cold food.   Having some sort of locally generated power would be nice, but gasoline fueled generators are loud, inefficient and handling gasoline causes more than a few fires.

 

Some of the items mentioned have very small power requirements - often just a few watts.  Since a person can easily produce 30 to 100 watts of power, the thought of using a small generator comes to mind.  

 

In the early 90s a friend and her husband set up a small DC generator on a bike for their kids so they could watch the Olympics on a small black and white TV.  It was crude, but seemed to capture the imagination of everyone who heard about it.  People would then ask about how much it would cost to build one and gave up on the idea.  These days you can buy small units for a few hundred to about a thousand dollars.  Anyone who is in reasonable shape should be able to produce about 100 watts for hour long periods.  You could easily charge several cellphones along with a laptop, but running your furnace fan would be a bit beyond what your muscles could provide.   Of course electricity is an ephemeral form of energy and you need a battery to store it unless you are directly powering something.

 

On the smaller scale where you are looking to replace C and D cells, people sometimes have hand powered mechanical units.  Some of these store energy in springs, but that turns out to be extremely inefficient. I haven't played with this unit, but it has a usb port to charge your phone and a small 200mAH battery pack so you can crank away and store a charge.  

The power from the generator is very small - probably under a half watt as the specs say you can get about 30 seconds of phone use with a minute of cranking.  Filling the battery (about 10 watt hours) would take quit a bit of work and wouldn't be fun.  Our legs are much stronger than our hands and don't tire as quickly, plus turning energy released from you metabolism into mechanical work is usually a bit under 20% efficient - which is why you get hot during physical labor...

 

But a single M&M has about 3.4 watt-hours of energy.¹  Hydrocarbon based fuels - and much of our food is just that - have energy densities on the order of a hundred times greater than batteries.²  Wouldn't it be great if we could just stuff a few M&Ms in our phones or laptops and be done with it?  Our bodies are fuel cells that convert food into mechanical energy, a bit of electrical energy, heat and other forms of chemical energy. It is possible to build fuel cells that convert hydrocarbons into electricity, but so far they are too large and expensive to find use in phones or laptops.  But someday ...

 

But what to do during a power outage?

 

My experience is that a furnace fan to move the heat from our natural gas furnace into the house would be awfully nice, but ours averages about 100 watts on a cold Winter day and my rowing only gives 6 to 8 watts.³  Since most of our energy is turned into heat a nice approach would be to invite a large number of people over for a party.  Each person gives off about 100 watts and if you could have them dance or commit some other form of exercise you might be able to raise the room temperature to a comfortable level.

 

The alternative you use is local heat and insulation.  During the day you sit in the sunlight and wear a sweater.  When it is darker you wear several sweaters or a down coat. You cover all of the windows to keep whatever heat you have. And you suffer a bit.  The Summer is worse as cooling takes more energy than heating for a similar size temperature change.

 

Rethinking the electrical grid would be nice.  We have underground power in our part of town, but it is fed by higher voltage lines that run through a wooded area.  The infrastructure is over 50 years old and tends to be problematic.  In the past two years we've only had electricity 97% of the time and only a bit over 98% over the past five^.4  Electricity is something you really want with yearly up-times minimally at 99.9% and downtimes no longer than a half hour at a time.⁵

 

But assuming you can deal with the heat and lack of refrigeration, the next items are lighting and communication. For some communication is more important than heating.  This last outage destroyed cellphone use for nearly twelve hours.  It turns out our cable modem based phone was dead too - we had thought of that as a lifeline and need to re-think.⁶  A bike generator could supply some efficient lighting or rechargeable lamps, charge your laptop and keep your Internet modem running.

 

While it might seem nice to have a "smart grid", that isn't coming any time soon and it probably doesn't make sense to push it immediately.⁷  What needs to be pushed in the short term, and something that broke badly was the cellphone infrastructure.  These should have the ability to run for extended periods by themselves.  In areas like ours a week isn't unthinkable (you would want battery and a fuel powered generator).

 

I would tend to stay away from the little hand generators as they only do a limited job.  You can't supply a lot of power over a long time with your hand and these devices tend to be very inefficient to boot.  Apart from a serious stationary bike based generator and storage battery I would recommend batteries  Get lanterns and flashlights that use the largest cells normally available - usually alkaline D cells.  Another option is to use disposable lithium batteries as they have greater energy densities than alkalines and have much better power densities.   While expensive, they often can be stored for a decade and still provide good performance. You can get a cheap battery case and wire an old usb cable to charge your phone for a visit to Radio Shack and a couple of bucks.  Commercial disposable battery chargers for phones run $10 to $25.  These are going to be much better than $75 to $100 rechargeable external battery packs over the long haul!

 

If you only see outages up to a few hours get an uninterruptible power supply for your computer and modem (one unit can easily power both).  There are a lot of cheap units that don't work very well (their batteries need to be replaced once every two years), so I'd spend a bit of money if connectivity is important.  Any rechargeable solution needs to be tested at least twice a year.  

 

In any event it makes sense for many of us to prepare.  The frequency of large storms - even what used to be 100 or even 1,000 year events - will increase with climate change and our infrastructure isn't exactly robust.  One of those external costs associated with burning an excessive amount of fossil fuel...

 

And finally I should stress the experience wasn't entirely negative.  While sub 50° house temperatures towards the end were not comfortable, there was a lot of human good will everywhere - from the restaurants that gave away food or would deal with IOUs, to neighbors sharing rides and food, to the story telling with friends and family and a few beautifully clear dark nights that you rarely see in a densely populated area.  I also was able to spend a lot of time away from regular communication just thinking and reading. That was a real treat.  As a result we've instituted a couple of hours of zero electronic communication every night. So far it is great.

__________

¹ Guess how I found out?  A serving of plain chocolate M&M's weighs 42 grams and has 210 Calories.  I counted 122 in a 420g pile - about 3.44 Calories per M&M.

² An M&M has an energy density of 5 nutritional Calories per gram - about 5.8 kW-hours per kilogram or 20.9 megajoules per kilogram.  (Calories, watts and joules are all just units of energy and one can easily convert to whatever is most appropriate for a calculation).  Carbohydrates (sugars) average about 17 MJ/kg, fat about 37, protein about 16.8, an average Li-ion battery is about 0.7, a lead acid battery about 0.1, gasoline is about 46. 

³ We have a 560 watt electric motor running the blower.  Our house is only 1100 sq ft and we average about 2 kW-hr of fan use per day in January.  There is no way I could supply enough power to run the motor directly, but I could if I used a battery.  I can supply about 150 to 200 watt-hours during my exercise sessions, but that leaves me spent. A small generator and mechanical transmission is probably 80% efficient.  Assuming charging is nearly 100% efficient I would need 2500 watt-hours of rowing a day.  That is more than an order of magnitude more than I can supply.  

⁴ In the past 24 months we were without power for 22 days spread over three major storms in roughly equal amounts.  Two times in cold weather, once in very hot weather. In the past 5 years we've been down 29 days for 98.4% uptime.  

⁵ A 99.9% uptime gives the utility 525 minutes of outage a year - a bit under 9 hours ...  99.99% is a bit less than 53 minutes.

⁶ When IP telephony was proposed for cable modems it was assumed that phone ready modems would have backup batteries.  The requirement was dropped by the FCC, but units have optional batteries.  We assumed ours had a battery, but of course it didn't so all of our lines were dead until we got a bit of cell service.

⁷ Smart grid is a somewhat nebulous term with too many meanings.  The general concept gives something that should be much more robust in immediate storm recovery, but the standards to get there aren't solid yet and this is very expensive infrastructure.  There are some areas where it makes sense to deploy developing technology as the problems that are solved are immediate and huge - climate change comes to mind.  Other areas require more study and thought. In five years to a decade we should be at a point where robust deployments can take place.

 

__________

Recipe Corner

 

Two seasonal items - something really quick and easy for Thanksgiving that is a nice change from the traditional cranberry sauce and a neat side dish with celeriac.

 

Thanksgiving Cranberry-Blueberry Sauce

 

Ingredients

 

° 12 oz cranberries, fresh or frozen

° 3/4 cup water

° 1 cup white granulated sugar

° 8-oz blueberries

° 2 tsp vanilla extract

 

Technique

 

° Combine cranberries and water in a medium saucepan and cook over medium-high heat until the cranberries begin to pop, about three or four minutes.

° Add the sugar and blueberries and continue to cook, stirring occasionally  until mixture comes to a full boil. Boil for three or four minutes, stirring occasionally, until mixture thickens slightly.

° Remove from heat and stir in vanilla extract and transfer to a refrigerator-safe container and allow to cool to room temperature, then cover and place in the fridge. Chill until ready to serve.

 

__________

 

I love celery root - that terribly ugly lump of brown you see in some stores.  It turns out to have some fairly amazing properties and is soft enough that it trims up easily.  Just use a big sharp knife and slice away - and be careful to wash it as there are deep crevices where sand can hide.

 

I don't know what to call this, but it came together well and is a keeper..  Feel free to adjust ingredients and proportions as this was a first throw together.  Next time I'll probably use a good balsamic vinegar. It is really good with a whole grain bread!

 

Apple and Celeriac Bake

 

Ingredients

 

° 1 large onion, finely sliced

° 2 tbsp olive oil

° 750g vegetable stock

°  tsp cider vinegar

° 1 crushed garlic clove

°  3 thyme sprigs

° 600g Piece of Celeriac (peeled weight)

° one largish apple (I used a Fuji - what was crunchy and on hand.  Mine was 190g). 

° 50g almonds, lightly toasted, skinned & roughly chopped - probably great with hazelnuts

° sea salt and fresh ground pepper

 

Technique

 

° preheat oven to 400°F

° fry the onion in a pan with the oil over medium heat until soft and translucent.  Add the stock, vinegar, garlic and thyme and bring to a boil

° cut the celeriac into quarters and then thinly slide what is left.  Add the slices to the boiling mixture.  Reduce heat to a simmer, cover and leave for 15 minutes.  

° season with salt and pepper

° transfer about half the celeriac and onions to an oven proof dish (mine was a pyrex dish about 8x8 inches)with a slotted spoon. Thinly slice the apple and layer on top of the celeriac.  Scatter half the almonds over the apple and then add the rest of the celeriac and onions.  

° pour about 200g of the pan liquid over the layers and scatter the rest of the almonds over the top.

° bake for about 45 minutes