Tag Archives: PV

Off-The-Grid COMET models

Hello!

I’ve been working up some 3D models (using SketchUp) of the COMET as she may end up, or the “end result” models. These are likely to change as the design process continues and ideas solidify, but here was what I first envisioned The COMET to look like. Perhaps the rainwater harvesting system will change, and the solar modules might be in different places or as a separate array that pops up and can move around in order to collect optimum sun, but here’s my totally self-contained version of The COMET of the future.

 

Also, here’s one version of an “info sheet” that explains the COMET in a more comprehensive way.

What do you think? Is there anything else that a comprehensive info sheet about the project should include? I need some feedback!

Tagged , , , , , , , , , , ,

Solar RV Eye Candy!

I’ve been so caught up in technical details surrounding The COMET lately that I haven’t done a just-for-fun Eye Candy photo in weeks!

The madness ends now!

Here’s a wonderful image of a solar-powered motorhome.

Based on the size and number of those panels, looks like it’s about a 750-Watt system. I wonder if those panels tilt up for when they’re parked, of if they are snowbirds and just follow the peak sun. Anyway, it’s a beautiful and unique RV, I love the seafoam green accents 😉

Speaking of beautiful and unique RVs, a friend of mine just began working on a rare vintage motorhome called a Clark Cortez. He’s fixing it up mechanically and also planning to build the interior from scratch, as it is completely gutted right now. Apparently there were only 3000 Cortez’s ever built while they were in production between 1963-79. The people who are into them are REALLY into them, it’s like a club! After pouring over the owners and parts manuals that my friend had (which was way more fun than it should be…vintage motorhome owners/parts manuals are definitely the way to my heart!), which was as thick as a dictionary and had schematics for EVERY single detail of every aspect of the Cortez, I realized that a house not far from me has not one but TWO Clark Cortez’s in their back yard, one brown and on pink (!). Considering how rare they are, one person owning 2 Cortez’s is sort of mind-blowing! This family also has a vintage Winnebago and a couple of other 1960’s campers in their yard, so they seem like my kind of people. I’m considering knocking on their door (with my buddy who wants to see their Cortez’s interiors for ideas) and asking them how they came to own so many interesting, classic RVs, and hear their story…but maybe that would be an odd thing to do?

The Cortez at the RV Hall Of Fame, a lifetime destination for me.

Anyway, enjoy the camper eye candy, and later I’ll share some photos of my fermentation set-up that I accomplished for less than $5, which was my goal! (I found the greatest gallon glass jar at Salvation army – wait till you see).

Until then!

 

Tagged , , , , , , , , , ,

Cheap Green RV Living Resource

Good Morning!

I have been a big fan of the website cheaprvliving.com for a long time now. It is full of really useful information from Vandwellers and Fulltimers who have been living the alternative, mobile lifestyle for a long time, in everything from minivans to school buses. I really appreciate the no-frills attitude of the site and the vans/RVs/camper conversions that they feature. They have simple ideas about simple living.

I just recently discovered that cheaprvliving.com launched a sister site, called Cheap GREEN RV Living, and it’s all about how to live more sustainably in a camper, bus, converted van, or car. There are lots of ideas for off-grid alternative energy systems, boondocking tips and tricks, and how to respect the planet while living more freely. Some of the articles on CheapGreenRVLiving.com talk about how to pare down your possessions, some talk about the logistics of using the toilet, and others give detailed step by step instructions for installing a PV system on your van’s roof. My favorite page is the product reviews page. This guy is super honest and has actually used all of the products he reviews, so I found this article really useful.

Anyway, check out both sites if you haven’t already, you won’t be disappointed!

Tagged , , , , , , , , , , , , , ,

All-DC Solar Power System in The COMET

Here’s a follow up to the last post, where I talked about how to calculate your (kilo)watt usage and shared my own table showing what electricity-using appliances I will have. Here’s why that “AC or DC” column is important.

These are the actual modules that I have. 3 x 185W modules. Thanks Cotuit Solar!

I want to design a PV system for The COMET that is DC-only, and has no AC inverter (which turns the DC power from the panels into the AC power that comes out of your wall sockets). The reason is because of the nature of inverters for PV systems: inverters are the single most expensive component of a PV system. They also are the point at which 20% of efficiency from what the panels are actually producing gets lost. That means it takes 20% of the energy you are producing with your panels to power the inverter. That’s a lot of lost energy, especially in a small system! So I am devising a unique system that requires no inverter.

Here is a diagram of how the system will look. Modules, charge controller, battery bank, then DC load or outlets.

In order to do this, I need to convert ALL of my electricity-using appliances to run on DC power (see previous post for details, but basically everything in The COMET runs on DC anyway, except the laptop computer, which I will buy an DC power adapter for ($20 as opposed to $2000 for an inverter). It isn’t unusual for camper and RV appliances to be wired for DC and use only DC, so that’s another reason this conversion will be feasible. I’ll also need to make sure everything is running at 12V – meaning I will need a 12 V battery system.

DC plug

I have seen some grid-tied systems that use this principle to power what DC appliances they have (check out this Instructable as an example). For example, charging all of your fans, lights, cell phones, ipods, and basically other electronics with car chargers, with power from the panels using no inverter (and maybe even no battery if you only want to access the free power during the day). However, my system will be very unique in that it is off-grid and completely DC. I’ll have wall outlets like everyone else – they’ll just be DC and look like the ones in your car!

Small 150W inverter for just-in-case AC scenarios.

The one thing I am worried about with this system is not having the flexibility to use anything with an AC plug. Who knows what will come up, there may be a day when I need to test something or use an AC plug to power something. Of course, I can only plan so much. For this scenario, I will have a small car inverter (probably somewhere around 300 W) that can plug into the DC wall outlets when I need it (or maybe it’s mounted in the wall somewhere, but I see it as being more of an emergency use kind of thing).

I’m still working out the kinks, but this entirely DC system will save me a lot of money and be much more efficient than an inverter system. I’ll keep you updated as I experiment with this concept!

 

Totally unrelated, but I just wanted to point out how awesome the Habitat for Humanity ReStore is. I went to the one in Worcester on Saturday, because I was driving by, and they happened to have a few click panels of cork flooring. I picked them up for a $1 and will hopefully be able to use them in the bathroom!

Tagged , , , , , , , , , , , ,

Mobile Solar Electricity with PV

Hey everyone! Happy Monday!

So as you may know all last week I was in Vermont attending an intensive photovoltaic design/installation class (at the Yestermorrow Design/Buidl School – check it out here). By the end of the week, I realized it would be very difficult to sum up everything I learned, so I think I’ll just get into it little by little. There are so many factors and variables when designing a PV solar electric system for your (tiny) house or mobile house. Weight and stability came up a lot, as well as mobility concerns with roof mounted systems.

For today, I thought it would be fun to introduce you to some of the stuff we covered in the course with an activity you can do yourself. It’s really enlightening and will definitely surprise you if you’ve never really thought about how much energy you use.

For this it’s helpful to know that Volts x Amps = Watts. It’s also really helpful to have a Kill-A-Watt meter around, so that you can plug in your electronics and see how much power they use.

Here’s a Kill-A-Watt meter like the one I used.

Also, note that my calculations are in Watts, because I am dealing with mostly smaller electronics and appliances, but usually if you were sizing a whole house system or something larger you would use kilowatts.

*Efficiency first! Make sure you consider your efficiency before sizing a PV system. Consider phantom loads, insulation, and other factors to see how you could use less in the first place! For example, I am choosing not to have an electrical pump (my faucet will have a hand or foot pump which creates water pressure, and my solar shower will be gravity fed). Because I am going off-grid in a small space, I really have to be careful about where I use electricity.

Basically, we are calculating how many watt-hours we use in a day in order to be able to accurately size an off-grid solar PV system. Finding out how much energy you use in day is really cool, and I feel like it immediately makes you think more about what you use and when. I made a chart with the headings Appliance, Watts, Hours/Day, and wH/Day in order to break down my energy usage. From this I could figure out how much energy I use in a typical day. My chart is pretty simple, and I only have a couple of power-using appliances. The stove and heater in The COMET run on propane (PV cannot efficiently produce heat with electricity). Like I said, no electrical pumps for water. All of my lights will be LEDs to cut down on watts (which is generally an expensive endeavor – to replace all of your lights with LEDs – but I only have about 4 wall sockets so it’ll be affordable and worth it in the energy-usage long run!). Also, I overestimated in some cases just to be safe.

Here’s my chart!

So you can see that I only have a few electricity-using appliances. The other thing to consider here, especially for me because I spend a good amount of time on the road (and even more once the I live in The COMET camper) is that I often charge my phone and other things in the car. Anything with a USB port usually gets re-charged on the road.

I hope this is useful in helping you figure out how much energy you use. For some of your appliances, you will be able to see how many watts it uses on a spec sheet or by looking it up online. For others, it’s just easier to plug it into the Kill-A-Watt. And if you have the voltage and amperage of an appliance, you can figure out the watts by multiplying V x A. The total watt-hours/day ( that 790) will be integral to figuring out how much PV you need for an off-grid system. I will go into that later!

At this point, the DC column at the end of the chart may not make sense, but I will do another post later about why that column is so important! I am figuring out a way to have a much more efficient PV system than most, and I think you will find it interesting to think about! So stay tuned for that later on.

Tagged , , , , , , , , , , ,

Photovoltaic Installation at Yestermorrow School

The last 5 days I have been in a very intense class learning the ropes of PV installation. We’ve done sizing of a system (I haven’t done this much math since high school!), flash-mounted roof mounts, and we’ve wired up our solar panels. Based on my calculations, I think I have way more than enough PV power with the three panels I recently got from Cotuit Solar.

Tomorrow is the last day, when we finally plug the panels into the combiner box (then charge controller, then AC breaker, then batteries, then inverter – whew!) and see how it all fits together. This class has been super enlightening and I can’t wait to share what I’ve learned. The Yestermorrow Design/Build School offers a learning experience like no other. It is really amazing here. Every person I meet is either building a tiny house (or has built one) or is working on an Airstream retrofit/renovation or already lives in an Airstream. My kind of people!

Anyway, this is all I have to show you for now, more later!

And here’s the tiny house that’s currently in the parking lot outside!

Tagged , , , , , , , ,

Yestermorrow update + The Greenest House in LA

Hi!

I have just arrived at Yestermorrow Design/Build School in VT for my Solar Electric Design + Installation course! I am very excited, and the class begins tonight, so we are jumping right in. I’ll be here for 5 days learning how to design and install a PV system for The COMET. My experience here will also come in handy when I help Beth Ferguson of Sol Design Lab (check out the pumps!) install a solar powered bus stop installation on campus at Hampshire College in Amherst, MA next month.

 

 

Okay, here’s a cool project!  “On Begley Street”

On Begley Street

For all of you sustainable design/green building fans: I was listening to “ACE On The House” (Adam Carolla’s carptentry/construction podcast) the other day and heard Ed Begley Jr., celebrity/environmentalist who was driving a solar powered car way before it was cool, talking about his new building project. He and his wife Rachelle are building a LEED platinum home (I believe it is net zero energy?) in place of their existing one. They have had their original home completely deconstructed so that each piece can be re-used in some way. Their new home will be “The greenest home in LA” and will be an example of sustainable building practices. They hope that others in the neighborhood will follow suit!

I think this is a great idea. If more celebrities had more gardens and less lawns, people might be inspired to follow their lead.

You can support their green building project via Kickstarter. They are asking for funds to be able to have a webshow that details “How to build a LEED platinum home”. I can’t wait to see the upcoming episodes!

 

Tagged , , , , , , , , ,