Solar Panels??

Exactly why the PCT hikers I spoke with said the solar was a weaker option the farther north (and denser tree cover) they got.

The battery bank is a great idea, and the Brunton energy bank I mentioned above is a good deal. I saw you snatch the Solio up in Gear Swap, that was a nice price.

We hiked the JMT this summer north to soutch for three weeks and used a PowerFilm USB + AA Solar Panel Charger to charge AA batteries (Sanyo Enelope) for several devices. We needed daily 2 batteries for our GPS (Oregon 550), every 3-4 days 4 batteries for our SteriPen Classic and every 3-4 days 2 batteries for our camera (Canon PowerShot).
During our preparation hikes we had first experimented with the Solio charger, but that didn't work for our purposes and required to first charge its internal battery and then charge our AA batteries via an adapter.

With the PowerFilm we could charge our AAs directly. It also allows to charge USB devices directly. We never used that feature and I can't say anything about it. When using it you need to have 2 AAs in the charger.
There is also a version that charges 4 AAs instead of 2 which has 6 panels instead of 4 (but doesn't allow USB). We will test it this year on the JMT.

The PowerFilm charger was tied to the top/back of my backpack which is not an optimal angle while hiking south, but we still got all the charges we needed from it.

…

Manfred:

Sounds like a system that works! Is this the model?

Although the technology / efficiency is steadily improving, the bulk, weight and waiting time still can't match the alternative of throwing in a couple extra rechargeables — unless one is going on a long trip or thru hike like yours.

I've been fascinated by solar batteries since high school ('70s) and look forward to the day when they become efficient enough to qualify as truly light weight "quick chargers". One day.

Bob, they were strapped to the front of my shoulder straps. And they have an internal battery so no wires have to be attached while strapped on the pack. It worked very well on the jmt as you are above the tree line most of the trip. It still does get charge when cloudy.. obviously not as much as clear sky's..

I did have my iPhone on airplane mode and took the sim card out to maximize battery life. I used it mainly for audiobooks and GPS apps. After a full days charge I would get about 20-25% on iPhone. And i used a lot less than that per day so it stayed fully charged the whole trip. Same with my flip cam..

Jason,

That was my thinking this morning. I rarely use 25% of a full charge on my iPod Touch.
The most I'll use with my Blackberry is about 50% in a day. And, that's a busy day of talking. If it happens to be a day of mostly texting, I use a substantially less.

BTW my iPhone is on the way. Always thinking multi use here.

Anyway, on the occasions when I'll be using my new DeLorme PN-60, I can't imagine using it all day. My estimate is probably 15% of the day at MOST. Honestly, I'll likely only use it 7 – 10% of the time. So, the most charging I'll need is about 35% of a full charge, for my iPod and GPS unit combined, since I never take my Blackberry into the back country. The Solio Classic charger just might work even in low light conditions since a full charge might never be needed.

Benjamin,

Your picture shows a very similar model.
Ours charged only 2 AAs (not 4 as shown in your picture). Here is a link to our charger

Ours allowed to charge devices directly via USB which would be interesting for this discussion, but was not needed for our purpose.
We use it only for long trips (like going three weeks on the JMT). We like to have our GPS on all the time and geotag our photos afterwards using the track from the GPS. That requires a set of AAs every day. We were able to do that over the whole three weeks (even with cloudy days inbetween) by using it non-stop — meaning when the LED showed that the batteries were charged, we would exchange them with batteries from one of our devices and keep charging. Since we didn’t use the USB capabilities last year on the JMT, we will use this year the model that charges 4 AAs.

It uses 6 panels instead of four and thus charges the batteries faster. It serves our purposes better since we also use the Steripen Classic that requires 4 AA.

Thanks, Manfred.

I am a huge solar advocate. We have a tent trailer that has 250 watts of panels. Prior to our current trailer we have owned for 5 years, we had another with 120 watts of power. I also have a sophisticated battery monitor that I have used over the years to measure amps in/out, etc. We have not connected our trailer batteries to the electric grid in 7 years. And we have camped well over 700 days and never had a dead battery. So some of the things about our tent trailer are appropriate for this discussion.

Number one: You need to determine how much power your devices will consume each day. That is how many amp hours (AH) you need to replace. Since we use lead acid batteries in our camper we cannot go below 50% of our battery bank's rated capacity, as the batteries can get damaged. Our panels are sized appropriately. In normal weather, even in the winter, our battery bank is usually fully charged by 10:00 AM. We are usually not in the camper during the day, so we need enough capacity to get through the nights. Typically our usage includes lights, water pump for dishes and showers, and operating a forced air heater during the night. We have replaced our 12 volt incandescent light bulbs with 12 volt fluorescent lights, which use less juice. We find LEDs do not work well for general lighting. Our refrigerator runs on LPG. We also have a LPG catalytic heater that uses no electricity and 75% less gas than the furnace. We use that when night temps get into the 30s F or below. The catalytic heater puts out about 50% of the furnace's BTUs and provides radiant heat. So sizing our system included a reduction in electrical consumers.

Number two: solar panels are rated at the max they can put out. With high quality panels like we use (Kyocera) we can get up to 95% of the rated power out of them under ideal conditions. For fixed installations like ours, there are other methods to get the full 100%, but not applicable to this conversation.

Number three: You need to determine how much sunlight your solar panel can collect. In So Cal in summer it is easy to get full power during the middle of the day. The season (e.g. winter) of the year and latitude (e.g. Seattle) can reduce this significantly.

Number four: The panels must be angled directly at the sun for maximum solar collection. This is not too difficult for fixed installations, but impossible while moving. If you cannot tilt panels directly at the sun, then you need a larger solar array.

Number five: Shade is a killer. Because of the construction of most panels, shade hitting 10% or your panel can kill 50% of the output. So a panel on the top of your pack can be cut significantly from the shade of a wide brimmed hat.

Number six: Clouds. Clouds will reduce the power output, but you can still get some output in cloudy weather.

Number seven: You need to size your solar system to anticipate all the items above. That is, you need much more capacity than your can theoretically produce each day.

Number eight: Worrying about charging your system. We do not worry about our panels and don't check the system much anymore. They just sit up on the roof and keep things in balance. We can go for many rainy days, and have enough reserve capacity to get by for a week of constant rain. Although we do not do it, we can power a microwave or an electric toaster. Also will your panel get damaged in use? Our panels are warrantied for 20 years and are designed to withstand hail.

Bottom line: You need to do a lot of research and calculations to size a system, as Bob G has posted earlier. Bad weather and shade can leave you with no power to run your electrical devices. For this reason I do not carry much in the way of devices when backpacking. Normally a camera and a headlight. If the camera goes dead, I will live. A spare battery for the headlamp and it will last for a very long time. A map and compass instead of a GPS 99% of the time. I cannot get cell phone coverage in most places I hike, so it stays in the car. Also if I had to constantly mess around with positioning my solar panel while walking, I would find the trip less enjoyable and frustrating.

Here is a picture of our panels.

You got rid of that Starcraft that you did all those great mods too?!

Nick, it is easy for you to be a big solar advocate. You live in Southern California.

As you start moving north, the practicality of solar reduces. By Portland, it is marginal. By Seattle, forget it.

–B.G.–

>You got rid of that Starcraft that you did all those great mods too?!

Terri, look closely at the upper right of the picture I posted. It is there in the background. I am probably going to give it to my son. I just couldn't part with it when we bought the big one. For those who are wondering what Terri is talking about, the little camper in the background is a very small tent trailer. In 2003 my wife and I gutted it and re-built it from the ground up with amenities that are often found in larger travel trailers.

Terri, I hadn't noticed or put "ncalcamper" together. Good to see you here on BPL!

> Nick, it is easy for you to be a big solar advocate. You live in Southern California.
> As you start moving north, the practicality of solar reduces. By Portland, it is marginal. By Seattle, forget it.

Bob, no argument here. That is why I live where I do. Solar is not for everyone.

Off topic, but…

Nick — given your experience with solar panels… have you installed them on your house? If so, would love to hear what you did and your resulting experience!

As you start moving north, the practicality of solar reduces. By Portland, it is marginal. By Seattle, forget it.

Strongly disagree.
Germany has the highest rate of solar uptake in the world and very high power outputs to the grid, and is approx 51 degrees North.
Yes, it makes it a bit less effective. The poorer weather to the north has a greater impact than anything else (panels can / should be angled quite severely towards the south), but given a reasonable surface area and decent efficiency (especially in how the power will be used) it remains very effective.

My own experience with solar is this – I tried a 3 watt / 5v SolarFocus panel while bike touring in Italy in the middle of summer, and it couldn't keep my iPhone charged using it for about an hour of GPS a day, charging 12 hours a day.

I now have a 10-watt / 12v PowerFilm fold-up panel (it had the best power-to-weight ratio of any panel I looked at. The roll-up ones, and even competitors similar folding models, are heavier).
I plug it into a lightweight Ansmann DigiCharger Vario Pro charging unit that can charge 2 AA/AAA's, USB (for iPhone), 3.6v lithium, 7.2v lithium. And it has a "backup" mode where you can put in a lithium battery and power the USB port from only the battery. It can charge at up to 1000ma (2 hours to charge AA's from dead) in good sun.
So I can charge my headlamp, iPhone, DSLR battery, and Steripen batteries from a single lightweight device at any time of year in overcast skies. It works well and I normally only bring it out when I'm stopped because it charges so quickly.

[solar] "it remains very effective."

In the USA, it can be effective, but not cost effective. The economic prove-in point around Palm Springs is 2-3 years. By San Francisco, it is more like 8 years. By Portland, maybe 15 years, and Seattle is maybe 25 years. There are lots of local variances, like where they get cheap hydroelectric power.

Germany may have a high rate of solar uptake simply because their conventional power is much more expensive.

Where solar power can be practical is somewhere where there is no conventional power grid. That might mean out on a backpacking trail, but it is more likely to be a hundred miles from the nearest power line in Africa.

–B.G.–

Yeah, I won't argue with that at all. I view the benefits of grid-independence as being the main reason to consider solar, not economics. I guess economics are the reason the uptake is so great in Germany, but my point was more that solar panels can work *technically* just dandily in northern climates irrespective of economics.

Ben,

No I haven't. Here is the reason. The only way you can realize a ROI (amortize your costs over 20 years – which is what most quality companies warranty their panels for) is to take advantage of the federal and state tax credits. This means that other tax payers would have to pay for part of my installation.

It is not as simple as mounting some panels on the roof. There are many ways to do solar. Most common is a large battery bank connected to the panels and a controller in between (think voltage regulator to make it simple). Now during the day an inverter or inverters change the stored power in the batteries into 110v and 220v. As you use power from the battery bank via the inverters, any excess beyond your consumption from the panels is stored in the battery bank. If you tie into the grid, any excess electricity beyond what you use and can store is sold back to the public utility… if your local power company is willing to purchase it. At night you run off your battery bank. If the bank gets low, then you pull any needed power from the utility grid. So this means you need room to store and maintain a large battery bank and deal with inverters and other components. And of course components can break and will need replacement.

A while back I priced a 5kW system at $50,000. This will probably produce an average of 30 kWH of power per day over the year in Palm Springs. However last year my consumption averaged 33.4 kWH per day (remember we need air conditioning for several months a year). So this system will leave me short about 1244 kWH for a year. Also, panels become less efficient over time. I have not factored that in.

Last year I spent $1,800 on electricity. Assuming prices do not increase (they will), in 20 years I will spend $36,000 on electricity. The system costs $50,000 (assume I pay cash). If we assume that my total cost will be double over 20 years, then it will be $72,000. Now Ben I know you… If I gave you $50,000 today, what will it be worth in 20 years after you invest it? A lot more than $72,000!!

Of course if I let the taxpayers absorb $25,000 of the installation (moral problem for me), then the ROI is there… but I can make more than $72,000 in 20 years with the $25,000 investment anyway. Today I think Federal and Calif tax credits can net you 50% of the cost, but I have not researched it thoroughly.

However, I think in the next 5 years we are going to see improved technology and lower prices and I may then go solar on the house. The problem for the past 5 years is that with so much government subsidy in the US and Europe, demand was sky high and it kept prices high. For example the Kyocera 120w panel I bought in 2003 for $495 was going for around $700 until the last year or so. Now a similar Kyocera panel can be bought for around $400 (best deal on the Internet). Also the residential solar market is just taking off and prices will get more competitive.

A friend of mine installed solar in his house a few years ago. Much more maintenance and inconvenience than I am willing to deal with now. But that is changing quickly. Sometimes it does not pay off to be an early adapter. Do you want to by an Apple Newton? :)

The solar experiment on my trailers has been a great success, and I am just waiting for technology to get better.

I have just installed 14 panels (about 2.5 kWh) grid-connected as part of a larger green renovation and it has been a booming success – our last electricity bill had a $148 credit. The reason is two-fold: one, we're now using nearly half the electricity we were using prior to the reno – for example, we haven't turned the aircon on so far this summer because we've found that the additional insulation is very effective at keeping the heat out, our ceiling fans are incredibly effective and the new cross-ventilation helps keep things comfortable, and because of the shaded, double-glazed north facing windows we don't use internal lights much either (and they're all CFL anyway). The other reason is that we get a net feed-in tariff (unlike Germany where there is a gross feed-in tariff) of 60 cents per kWh from our retailer. As it's high summer here now we get 8+ hours of daylight.

"A while back I priced a 5kW system at $50,000"

I'd be surprised if the system cost that now, especially because the cost of solar panels has nearly halved over the last year or so because of the Chinese factories coming on line – with RECs a 5kWh system here would be about $15,000.

Edit: I checked – about $30,000 before rebates and RECS.

"last year my consumption averaged 33.4 kWH per day (remember we need air conditioning for several months a year)"

33.4 kWh ?!!! That's nearly double what my family used in mid-summer, during school holidays, with the air-con on, when they were all at home – and you may be aware that Melbourne's a pretty warm place.

"The only way you can realize a ROI (amortize your costs over 20 years – which is what most quality companies warranty their panels for) is to take advantage of the federal and state tax credits. This means that other tax payers would have to pay for part of my installation."

Have to disagree with all that. Ultimately the reason why governments are willing to subsidise solar (or wind) is that it's no more expensive than building new power stations. So taxes can pay for new fossil fuel stations, new nuclear plants (which are REALLY expensive) or renewables. If private businesses build the power stations they will require a commercial rate of return. Distributed generation is a legitimate engineering concept.

By the way, your electricity rates look very, very cheap: both here, the UK and Japan are definitely more. I suspect that like petrol prices in the US, your energy costs are not being appropriately priced.

"However, I think in the next 5 years we are going to see improved technology and lower prices"

As I said above, when we got our quotes from our supplier the Chinese panels cost nearly half the "Australian" ones – $727 vs $1,290 (and the "Australian" ones were manufactured in China anyway). So we left the budgeted amount, added a bigger inverter and upped the number of panels. We may add a battery system as the next step.

"… Also the residential solar market is just taking off and prices will get more competitive."

As you noted re Europe, demand doesn't bring down prices – it's supply that does.

It to bad Montbell does not manufacture their SC17 solar charger for backpacking any more. I picked one up around 1996 and I love it. The charger is a 1.7watt multi crystalline cell developed by Kyocera that the same cells used used in power gird cells, it's mounted in resin plastic weighs 8 oz. is 4.5 inches by 6.6 inches and can charge 4 aa nicads only in 3 hours or less. This charger is developed for 700 ma AA baterrys but I have charged 900 mA with no problem and charges quickly.

I have talked to montbell usa about bring it back and revise it to charge nimh cells but they said that it is highly unlikely they would bring it back in to production .If it could charge nimh cells it would take about about 6 to 8 hours to charge a 1800 mA battery.
Here's a archived backpacker link on the solar charger.
http://books.google.com/books?id=AOMDAAAAMBAJ&pg=PA98&lpg=PA98&dq=montbell++solar+battery+charger&source=bl&ots=aBB9ew2lYN&sig=6xvSJj0sL4BgLB7ONVrlO58Ootg&hl=en&ei=s24sTZ2uG4yisAP8_OXcBg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCkQ6AEwAA#v=onepage&q=montbell%20%20solar%20battery%20charger&f=false

Great discussion, Nick and D W!!

Yeah, I've been intrigued with the idea of solar power for years now. But I'll wait a few more years for the reasons that Nick detailed. Right now, it's still not economically efficient here in the States. But with the combination of improved technology and competition (e.g. China) — prices will come down. I live in Pasadena (southern Cal) and my roof is ready. :)

Ben, if you look at the retail price on solar panels, you can be deflated. However, there are some available at cheaper prices. Years ago, there was an early solar project out on the Mojave Desert. A year or so into the project, some problem was detected, and the whole project was dismantled. The slightly used solar panels came onto the surplus market at about 10% of the normal cost. A buddy of mine snatched up about 2kW worth and now has those installed on his house near San Jose.

Also, as is mentioned here, supposedly the Chinese-manufactured solar panels will be hitting the market with pricing substantially less than the traditional manufacturers (like Siemens).

–B.G.–

DW,

Some great points. Your solar installation included assessment and upgrades to other items in the house. Similar to what I did with our trailer. I measured my consumption and adjusted. Biggest consumer by far was the furnace.

We use 33 kWH per day. A couple things. My HVAC system is 32 years old. We will be replacing it soon. Average high temperatures where I live:

Jan – 70F
Feb – 75F
Mar – 80F
Apr – 88F
May – 95F
Jun – 104F
Jul – 108F
Aug – 107F
Sep – 101F
Oct – 91F
Nov – 78F
Dec – 70F

In the summer, 115F is not uncommon. I have seen highs up to 125F.
I work from my home office running computer equipment 8 – 12 hours per day.
We have an electric range.

Just a FYI. US Electric Power Sources 2009:
Coal = 44.5%
Nuclear = 20.2%
Natural Gas = 23.3%
Hydroelectric = 6.8%
Petroleum = 1.0%
Other = 0.3%
Source is the US Energy Information Administration.

Also the US has huge natural gas resources and natural gas use is increasing.

I get our electricity from Southern California Edison, which is part of a publicly traded company (Edison International). Southern Calif Edison's Net Profit is 6.8% of Sales (I do not know how much power they purchase from the Government). You know my thoughts on government involvement in the economy. Lets not go there on this discussion. However, 20% of the electricity in Southern California is provided by the San Onfre Nuclear Generating Plant. Ownership of the plant is as follows:
– Southern California Edison (SCE) (78.21%)
– San Diego Gas & Electric (20%)
– The City of Riverside (1.79%)

Regarding my electric cost… I pay more than some people, as lower income users get discounts, which the higher income earners subsidize. No comment.

Regarding demand: Demand increased prices, and as supply increased to meet demand, prices began to drop.

Regarding China: If the panels are high quality, they will be cheaper than the current best products on the market. However for those who care, will Chinese produced panels create a larger manufacturing carbon imprint than other countries? Less regulation in Big Red. Pick your poison :)

Hi Nick

Thanks, I call what we did a renovation, but in practice we completely rebuilt the place. Our aims were to add space (for our growing family) whilst not substantially increasing the footprint of the house, to introduce zoning, to minimise water use, to collect sufficient rainwater to keep our garden alive through extended droughts and to make the house more energy efficient (largely to shield us from the large increases in gas and electricity prices being introduced here). Melbourne has a large temperature range – about 45 C range from mid-summer to mid-winter and we wanted it to be naturally comfortable in both, instead of uncomfortable in both. We wanted to make the house solar passive but it faces the wrong way (the living areas face south – which is the wrong direction in Australia) and is made of timber and plaster, so we also needed to introduce thermal mass. And we have very noisy neighbours. And I wanted somewhere to park my bikes (although we don't have a garage or off-street parking, so I do have my priorities straight).

What we and the architects came up with was a pavillion with double-glazed north facing windows which was attached to the original house by a walkway. The pavillion has a kitchen and living room, so in the old house those rooms were converted to a bedroom and study/library. The eaves are positioned so that there is no direct sunlight on the windows from mid-November onwards but the winter sun hits the centre of the room. To get the sun in winter we had to slice off a portion of the original house's gabled roof: the new roof is angled at 21 degrees, which is the lowest the sun is here in winter. The floor is a polished white concrete slab studded with orange and black recycled glass – so it looks like terrazo, it soaks up the sun in winter and feels cool in summer. We added significant amounts of bulk and reflective insulation in the roof (about ISO r9.5 in summer – about r45 by the US measurement). We also added bulk (sound-blocking) and reflective insulation to all external walls and reflective under the floor boards. We sealed gaps to eliminate drafts. We put ceiling fans in all of the rooms and added custom-built double-glazed windows to match the period of the house. All timbers are recycled or FSC certified. Everything is low VOC. Anyway, the fans are great, we find that the temperature in the house is much more stable that it used to be and tends to be about 6 C cooler than the outside temp and we still have a decent sized backyard.

Re electricity prices – by my calculation you pay an average of about 6.7c/kWh. I just checked my last bill and we pay 19.5 c/kWh at the peak rate and 8.6 c/kWh for off-peak (NB: the Aussie dollar and US dollar are at parity, so there's no real conversion necessary). So your electricity would appear to be cheaper: from our point of view the local prices just accelerates the sense in installing PV and solar hot water.

Re the Chinese panels: the suppliers are a green business that's been around for decades. The factory in China is state of the art, a lot of the components are imported from Germany and they have the same warranties as the Australian or German panels – but obviously I can't vouch for their environmental footprint, although I think the supplier actually visited them.

And 125 F is pretty hot! On Black Saturday it was 48C in Melbourne and 49 C at my parent's farm, with a 60 k wind, so that's the hottest I have experienced.

DW,

Wow. That's a lot of planning. Would be cool if you could post some pictures. Perhaps if we are hijacking this thread we could start a new one in Chaff.

I installed 3 ceiling fans in our living room. I have a feeling they really don't lower the temperature much, but the circulating air makes it feel cooler. Maybe I will measure it sometime.

The desert I live in usually has low humidity in the summer. If I am at home alone, I often turn off the A/C off and run a small portable evaporative (swamp) cooler in my office. Decades ago before A/C was common place, swamp coolers were the norm. I would like to install a centralized evaporative system in conjunction with the A/C system. However the venting system needs to be much bigger than A/C, because larger volumes of air must be moved. My wife nixed the idea, because she doesn't want huge vents in each room. Plus it is not as comfortable for her. Since I have lived in the desert for over 30 years, I am much more acclimated.

Actually we have a sliding electrical scale. Once you go past a baseline, rates increase.

We have 3 large windows facing south (towards the sun), and two of them are single pane. The third was a huge picture window I took out years ago and replaced with solid glass blocks. It lets light in and helps insulate. I would like to replace the other two with blocks also… that way I can't see the neighbors :) but the wife nixed that idea. So we will go with double panes. One big improvement would be to up the insulation in the attic crawl space. I can increase it easily by 4 times. Also, exhaust vents would help. We have been in the process of remodeling our house for almost 10 years. And in the next couple of years should address the efficiency of heating and cooling system. We pay as we go (cash)… no borrowing from the vampire banks. But we pay ourselves first, which means we invest/save 30% of our gross income for retirement. That is why I look at the ROI of energy improvements, and it is taking so long. Good thing she doesn't force a backpacking gear budget on me!!