Suntrunks Project Summary:
Suntrunks are completely self-contained solar power systems that have all components
built into a rugged transportable case or trunk that can be set up and
operating in 5 minutes. They provide USB and
12 VDC outlets for small loads and 120VAC power for larger loads. The solar panels recharge internal batteries
each day and then the units can provide power even at night. I’ve built operating prototypes in 6
different sizes and they work very well. I need your help to rigorously test the units and to construct multiple second
generation units to incorporate improvements and reduce production costs. These solar power systems are a viable supplement
to batteries or fuel driven generators when you have emergency or remote power
Hi. I’m John Wennstrom and I’ve been
involved with solar energy for a long time. Way back in 1977 while in college I did my Masters Thesis on a solar
photovoltaic system that I had built and tested.
Today, I believe that solar energy
can do many more things for people in remote areas and especially in disaster
The “Suntrunk” idea came to me in
the days following the January 2010 Haiti earthquake. The news reports showed the terrible physical
and human devastation. The reports also
told of the great need for food, water and medical supplies and the total lack
of any power sources. No electricity or gasoline or oil. It was many weeks or even months before
generators and fuel supplies became available.
I also noticed that for the most part, during the day the sun was
shining. My vision became to invent and
package a complete solar system about the size of a suitcase or a trunk that
could be transported easily and set up quickly to capture a day’s sunlight and
make electricity available for many of the basic loads needed for the relief
A more recent example was Hurricane Sandy that
hit the US
last year. Millions of people were
without electricity and gasoline. In
events like these, small power sources can run phones, laptops, radios and
TVs. And they can provide lighting at
A small solar electric power supply can make a huge difference
to people just trying to get by day by day.
The first Suntrunk was in a hand
made wooden box about the size of a very large cooler. It had three 30 watt solar panels that would
fold out and lock in place, a heavy lead-acid battery, an inverter to provide
120 Vac power and the controls to make everything work as a complete package.
And It Worked!
With just a days worth of solar
input I could run lights, fans, power tools, radios.I could run or charge phones and laptops even
at night by drawing off of the battery. But it was hard to build, weighed over 150 pounds and was not really
rugged enough to be the transportable or useful power supply I had envisioned.
My vision has expanded from the
initial idea.Now that I knew it would
work, I though of the other uses for such a system. Developing nations with limited electric
grids or no utility power could use portable stations for many things. Solar energy could reduce or replace the use
of candles and kerosene for lighting.
These systems could meet many of
these very small loads. But why stop with just the smallest
loads. There are many mini solar
chargers on the market that can provide small lighting or small battery
Solar can and should be doing more.
What about power tools like drills,
saws, electric screwdrivers? What about
pumping water with a small pump? What
about running a small refrigerator for vaccines or other perishables? What about lighting a whole class room for
several hours during the night?
Solar can also provide new “economic
opportunities”. The idea is that if a
person has a power source for their daily needs that’s one thing. But what if they had a Suntrunk and a sewing
Other examples are; Lighting a shop at night, cutting wood with an electric saw, grinding wheat into flour or setting up a Web
connected computer to offer people a window to the world.
With renewed enthusiasm I set about
redesigning the Suntrunk to meet some very important goals.
1. They must be able to produce much
more power than the mini chargers. I
have now assembled a line of 6 systems that range in power from 10 watts of
solar up to 135 watts. The largest unit can
provide over 600 Watts of AC power for more than an hour with one day of good
solar input. The smaller SR60 unit could
run a small sewing machine all day on day’s worth of solar input. People can choose the size needed to fit
their specific load requirements.
2. It must be a complete
system. All the components needed are in
the trunk. There are no additional parts
to assemble on site. The Suntrunk
contains the solar panels, batteries, inverters and controls for a complete system. The electrical outlets come in three of the
most useful voltages. USB plugs for 5
volt power, 12 Vdc outlets for intermediate loads and then 120 volt AC power
for all standard AC equipment. The
wattage depends on the size of the system chosen.
3. It must be easily transportable. One of the problems with the first unit is
that it weighed over 150 pounds. Even though I put wheels on it, it was really
too much to move and position. The
problem was the lead acid batteries. The
units now all have Lithium Iron Phosphate batteries (LiFP). These amazing batteries are the next
generation of Lithium batteries. Compared to standard rechargeable Lithium batteries in use today,
they are safer and have much less environmental impact. But most important is that they are light
weight. For the same capacity of a lead
acid battery, a LiFP battery is 1/3 the weight. This makes my new systems much lighter and easier to move, position and
ship. The other problem with my first
unit was the wooden container that was hard to build and heavy. I now use military transport cases of varying
sizes to protect the internal equipment during transport. The larger cases have wheels and handles for
It must be durable and have a long usable lifetime.Many solar products use the lowest cost
components to market at the lowest price. They may last 3 to 4 years before a component fails or the battery pack
needs replacement. They sacrifice
performance, reliability and lifetime to get the lowest price. To be a useful and valuable energy source a
system should perform for 10 to 20 years. My philosophy is to use the very best components. The Suntrunks incorporate the following parts.
Panels: Crystalline panels are
proven performers and are produced a reasonable costs.They have tempered glass surfaces that won’t
fade and can be cleaned when needed.15
to 20 years of good performance can be expected.
Batteries:LiFP batteries have 3 to 4 times the lifetime
of lead acid batteries.Instead of
changing batteries every 2 to 4 years, LiFP batteries should give more than 10
to 15 years life.
Solar Charging Controller: By using
a Maximum Power Point Tracking (MPPT) charge controllers the solar panels can
collect and store about 20% to 30% more power each day. These controllers cost more but will pay off
over the long run.
Inverters: Inverters convert the 12
volt battery power to 120 volt AC power. I use only pure sine wave inverters because they will run virtually all
AC loads without problems and they are simply built better than the cheaper
modified sine wave inverters. This gives
you better performance and a longer life for the inverter.
5. Lastly I wanted the systems to be
useable by everyone. These systems can
be set up in less than 5 minutes. No
tools or technical knowledge is needed. Just
open the lid, then fold and lock the panels in place. There is no wiring or additional pieces to
attach. The system turns on with easy to
read switches and has a meter (not blinking lights) to see if the unit is
charging or discharging and how much battery power is left. They can be taken down just as quickly and
stored in their protective cases.
The Re-Designed Line Up
Over the last year we have built a
line of six solar chargers from 10 watts up 135 watts.
All of these units work well however
I need to do further testing to verify and improve performance and confirm all
features work well even under severe operating conditions. Also, these units were built one by one. I can see many areas where the price can be
reduced in the assembly of the second generation units. Also volume purchasing of parts will help me
produce the best product for the lowest cost.
So where do I go from here?
I’ve gone through the invention,
definition, proof of concept, re-definition, and have built a functioning prototype
of each unit. This Kickstarter project is a key part of the Development plan to
begin marketing these systems.
I intend to manufacture these units
here in Boise
once I have proven test results and accurate pricing for parts and assembly. I have formed a small company called
“Sunready Power”. Besides myself I have
a solar technician and web designer working on this project. However, at this point I have run out of funds.
My Project is:
1. Acquire test and data logging
equipment to thoroughly test my prototype units over the next three
months. Testing is essential to the
success of this endeavor. Needed
equipment includes both AC and DC data loggers. An accurate pyranometer for measuring solar input and temperature
loggers to examine overheat conditions that may arise. The proper functioning of all the parts
working together is off primary importance. Also the safety concerns of fusing, overload protection and overheat
protection must be tested. Only by data
logging the units operation under real conditions can I be assured that my
product is durable, safe and meets its performance goals.
2. Assemble Second Generation units of each of the prototype units. Using
what I’ve learned building the first prototypes, these new units will be improved in
terms of efficiency, weight and reliability. This activity will also provide
feedback on the assembly process and allow for volume purchasing of parts to
get a real cost of production.
My financial target is:
$36,900 of which approximately 20% will
be spent on testing equipment and activities and 80% will be spent on the
production of units and the rewards for backers.
My Project Timeline is:
When funding is secured I will
procure test equipment and begin purchasing parts for the assembly of the new
units. I estimate that assembly and testing
will start within weeks and continue through the end of the project. The production units will be ready for
delivery to backers within 3 months or by June, 2013.
Rewards for Backers:
All backers receive my sincere
thanks for helping me on this project. I’ll also produce a monthly status report for people to follow my progress. And you’ll receive a full color photograph of the Sunready team with the
new Second Generation product line that you helped create.
One of my tasks in life (some people
say it’s an obsession) is to increase people’s knowledge and understanding of
solar energy and its uses and capabilities. (My other obsession is throw-away
batteries. Please recycle your used
batteries and try to use rechargeable batteries wherever possible.)
Therefore my rewards for mid level
backers are Suntrunk accessories - made up of energy efficient LED study lights,
a rechargeable LED table lantern, an easy to use plug in AC wattmeter, and a
hand held solar intensity meter. These
devices will help you to become more aware of ways to use solar energy
efficiently and your solar environment. If you are considering solar in the future, these gadgets will help you
plan a system that will better meet your needs.
Larger backers will receive actual
working models of various sizes.These second
generation units will be of good quality and will have been thoroughly
tested. In the future I may contact you
for your feedback on the product. If you
wish you may continue to help me by offering your opinions and comments on the
unit you received.
About Me and Sunready Power
Even though I’m a licensed
electrical engineer, I’m also a bit of a hair brained inventor. I do know a little bit about solar
energy. I graduated college in 1978 with
a Bachelors and Masters degree in Electrical Engineering. My Masters thesis was on a solar photovoltaic
power system that tracked the sun and produced electricity and hot water. I built and tested the unit. In those days the best solar cells were only
about 8% efficient and cost about $20 a watt. They have come a long ways since then.
After college I went to work for an
electric utility here in Idaho
in their Energy Management Department and worked on testing new renewable energy systems
and conservation programs. After 20
years I left the power company and offered my services on a consulting basis on
energy conservation projects, solar PV projects and building custom solar
gadgets in my shop. also teach classes
on Energy Management and Conservation in buildings and give talks on Energy
Sustainability and Carbon Foot Printing.
I’ve built a lot of custom solar
systems for various customers. One interesting project was a sleek solar top for several low speed electrical vehicles. These vehicles had 380 watts of solar to boost their range.
However I’m very excited about the line
of Suntrunk units I’ve made from 10 watts up 135 watts. I believe these units can be a great benefit
to many people for security and safety after a disaster, for improving the
standard of living in areas where electricity is not readily available or fuels
are expensive and dangerous, and for many recreational uses.
In 2012 I started a company called
Sunready Power to develop and market these products when they are ready.
I have a shop and several people
ready to build and test the first batch of products.
The overall success of my vision depends on this
project. It will provide rigorous testing to prove performance and stepped up
production volume to find ways to lower the final price. Over the last two years I have put a lot of
time and personal funds to get to this point and look forward to working with
the Kickstarter community to take this to the next level. My budget is depleted and without your help it
will take years to do the work needed to make these systems available to
all who may need them.
if you believe like I do, that solar can do more things for more people, then
help me out with your enthusiasm and financial support. Thank you very much.
Risks and challenges
The biggest risks with offering this kind of product line are; 1. the reliability of the final units and 2. final pricing. First and foremost, the products must perform well to meet performance expectations. Basic testing conducted on the prototype units have lead to many changes and improvements in their performance. I need to do more rigorous testing and therefore need more accurate, and more expensive, test equipment.
Secondly, the viability as a consumer product depends on final pricing. By building multiple units I can take advantage of volume purchasing and streamline the assembly process. It is important that the units retail price be affordable for the buyers. These are the main challenges that this project will address.
I have been designing and testing solar electric systems starting in college and throughout my career. Testing to verify and improve performance is the key to making Suntrunks a viable and useful product for the many applications that they can address.
If you believe solar power uses can grow and help people all over the world then pledge $10 or more and keep yourself in the loop with this product's progress. And you’ll receive a full color photograph of the Sunready team with the new Second Generation product line that you helped create.
Thank You and you’ll receive an AC appliance meter. This handy meter allows you to quickly determine how many watts any plug in appliance uses. For solar applications it is very helpful to know the wattage of the loads you intend to run and if you get a Suntrunk system in the future it will be really helpful.
Thank You and you’ll receive a hand held solar meter. This is a solar meter like the one I use to check the level (intensity) of sunshine. It’s amazing how much the solar resource changes from morning to noon, winter to summer and with changing weather conditions. This meter will help you be more aware of your solar environment and if you get a Suntrunk system in the future it will be really helpful.
Thank you and you’ll receive all 4 of the Suntrunk accessories mentioned above. You get the USB light, the rechargeable table lantern, the watt meter and the solar meter. Now all you need is a Suntrunk solar system.
Suntrunk SR10 DC Only, 10 watts solar, weighs 11 Lbs, Size 13x12x6 inches, USB and 12VDC outlets, Best for DC loads from 40 to 80 watts, includes watt meter and solar meter, specifications may change slightly in final design.
Suntrunk SR20, 20 watts solar, weighs 23 Lbs, size 18.5x14x6.9 inches, USB and 12 VDC and 120 VAC outlets, Best for AC loads from 50 to 100 watts, includes watt meter and solar meter, specifications may change slightly in final design. You may choose a smaller Suntrunk if it better meets your needs.
Suntrunk SR30, 30 watts solar, weighs 32 Lbs, size 23x15x6 inches, USB and 12 VDC and 120 VAC outlets, Best for AC loads from 100 to 200 watts, includes watt meter and solar meter, Case has wheels and slide out handle for easy movement, specifications may change slightly in final design. You may choose a smaller Suntrunk if it better meets your needs.
Suntrunk SR60, 60 watts solar, weighs 80 Lbs, size 33x22x12 inches, USB and 12 VDC and 120 VAC outlets, Best for AC loads from 200 to 400 watts, includes watt meter and solar meter, Case has wheels and slide out handle for easy movement, specifications may change slightly in final design. You may choose a smaller Suntrunk if it better meets your needs.
Suntrunk SR90, 90 watts solar, weighs 118 Lbs, size 33x24x19 inches, USB and 12 VDC and 120 VAC outlets, Best for AC loads from 300 to 700 watts, includes watt meter and solar meter, Case has wheels and slide out handle for easy movement, specifications may change slightly in final design. You may choose a smaller Suntrunk if it better meets your needs.
Suntrunk SR135, 135 watts solar, weighs 138 Lbs, size 35x30x19 inches, USB and 12 VDC and 120 VAC outlets, Best for AC loads from 400 to 900 watts, includes watt meter and solar meter, Case has wheels and slide out handle for easy movement, specifications may change slightly in final design. You may choose a smaller Suntrunk if it better meets your needs.