Alternative Power recommendations
Quite a few of our clients live totally of the grid, and we think that is pretty cool! The info here will be very helpful to anyone thinking about alternative energy.
Before you spend a lot of money on your system, there is a lot of theft of PV panels and gear, especially on the neighbor islands in remote areas like Puna on the big island. Do not just jump into PV without first contemplating the safety of your location, and how you plan to protect and secure your equipment. After doing this, the next thing to contemplate is – do you have sufficient sun or wind on your property? If you are building in Puna, wind is generally lacking for most. The beauty of wind is if you have some, you might be able to keep your battery arsenal at a healthy voltage at night without running a generator. Which brings up another important point- the easiest, cheapest, most efficient and greenest way to go as far as having alternative power is to be hooked up to the grid. Why you ask? Well, if you are being powered mostly by PV panels during the day, and you are off-grid, your battery arsenal will most likely be maxed out by 10 am, and all that power you are producing via those panels is being totally wasted because if you were to over charge that arsenal, you quickly destroy it. If you are on the grid, you spin your meter backwards, the grid holds that energy, and delivers it back to you whenever you need it, even at night, with no need to fire up that generator. Refrigeration makes it so you generally will need to run that generator much longer, or turn off the reefer for some time every night as refrigeration pulls a massive amt of power. Think about that one for a while!
The most efficient refrigerator we know of is made from a small chest freezer with a special thermostat installed to make it operate as a refrigerator instead of a freezer. It is not as convenient as a side by side unit, but sips the power due to superior insulation, and minimal cold air escaping due to the door being on top vs on the front. Going off the grid requires a major shift in your life, requiring thorough inventory of power use and specific appliances and etc that sip the power. If you are not willing to go thru this process, then forget living off the grid. This chest freezer conversion is not expensive, and saves a massive amt of power consumption. Because of
the amt of power conventional refrigerators consume, many buy propane powered reefers. They are pretty effective but small and much more expensive.
Be prepared to go thru a bit of propane, which is not terribly cheap. They beat running a generator all night! And not having to run that generator at night means no carbon monoxide getting into your home either. Hot water and cooking round out the other two high energy consumers. Off or on grid folks can use either solar hot water or on-demand propane hot water, both work well if designed well. Gas for cooking is a no-brainer for off grid folks, and on grid folks can benefit from the superior properties of gas cooking. Every chef worth his salt insists on only gas cooking, electric cannot compare! If I were totally off-grid, I would want to have wind, lower my power needs and produce pretty much what I need and not have a massive energy production infrastructure nor a massive battery arsenal. Why? Batteries require a lot of maintenance if you want them to last and serve you well.
The irony is that being off grid means the more batteries the better to store power when the sun is putting out the most energy. With enough batteries, you do not need to run the generator at night normally, and with that efficient refrigerator described here, it is possible to not have to run the generator at night if you use power gently and have enough battery storage to hold it. Grid tied systems have no batteries, and they are best with lots of panels vs off grid needing much fewer panels, and are best with a large battery arsenal. There is no way around this process, it costs money and requires effort and time and thought. Here are some things to consider that you may have never been told:
PV Basics & Recommendations
Basics first- With an off-grid PV or PV/wind system, you have PV panels and/or windmills which feed into a charger/controller first, and then the energy is delivered into your battery arsenal. This charger/controller makes sure that your arsenal receives this energy at a controlled rate and voltage, and it protects your arsenal from becoming over-charged, which is crucial to your arsenals lifespan.
Without a doubt, you want to buy an MPPT type charger-controller. Outback company produces the best products. Do not buy hardware made in China
except for ET brand pv panels, which are accepted to be of good quality by most everyone. The good news is that if you use an MPPT charger-controller, you can work with any pv panel, even panels designed for on-grid applications will work fine. As of this writing, the USA made sharp 250 watt panels are very good. ET solar panels are also good, and less expensive. They are made in China and the industry in the USA all say they are good quality. Never trust anything made in China without doing some research first! Some things are good, and most electronics made in China are a waste of money and cause frustration.
PV panels getting installed on our Lava Runner featured in research paper published by the Natl. Assoc. of Realtors
PV system electrical equipment
Control panel for the system which
monitors your charger-controller and inverter
Then, depending on the voltage you have designed your battery arsenal to be, you have the appropriate inverter which converts the power stored in your arsenal from whatever voltage it is at to 115 volts, which is standard household voltage for everything except 220 volt things, which most people would not have if off-grid.
You do not need 220 volts. There are 120 volt clothes dryers that work quite well. It is recommended to run your generator when drying or washing clothes so you avoid running so much power out of your arsenal. You can do high energy things in the middle of the day when your panels are producing maximum energy, but drawing a lot of power through your arsenal lowers its overall life expectancy, so there is a constant balancing act when off-grid. Refrigeration is a constant need that consumes a lot of energy, so running your generator when washing and drying clothes makes a lot of sense. Living off-grid requires being quite conscious of how much power everything consumes and when it makes more sense to run a generator so you avoid stressing your arsenal. Being grid tied means you do not need to be so conscious and careful because there is no battery arsenal, and as such, there is naturally no battery maintenance. The one common concern though is energy efficient appliances, especially your refrigerator. On grid or off, power costs real money, so it pays to run energy efficient appliances. Being off grid means you generally MUST run the most efficient appliances.
Keep it simple! 12 V inverters are not as efficient as 24 or 48 V inverters, BUT- a 12 V system means much more flexibility with your battery arsenal. Why? Because lead acid solar PV batteries are typically 6V per each battery, so making a 24 or 48 volt arsenal means a lot of batteries, and if one or more individual batteries start crapping out on you, they will drag the entire arsenal down to the performance of the worst battery, so that behooves you to change those bad ones out, then as time goes on, the arsenal in general inevitably loses performance, you change out the entire arsenal and go all over again.
Our solar supplier has advised us that he actually recommends going with 48V systems for many reasons that are too technical for this discussion. The battery situation is what it is if going 48V, and the batteries are about $500 each, so 8 of them is $4k, and will give you 2-3000 watts of power per day. That is enough power for a couple, but generally not enough for larger households.
There are other battery technologies, but as of this writing Aug 2013, the Surrette 6V, 400 AH lead acid batteries are most recommended. Regardless of what kind of batteries you choose, with 12 volt systems, the whole battery scene is much cheaper and easier to maintain. Also, 12 volt inverters are a lot cheaper, BUT less efficient. The bottom line with off-grid systems is really evaluating your energy use, and minimizing it. The more you push electrons into and out of your arsenal, the faster you wear it out.
The more batteries you have, the longer they last,
the more energy you can store, the least time you will run your generator and the less wear and tear you put on them.
You can get 10 years of use from the Surrette lead acid batteries if you use an MPPT charger controller and do the periodic maintenance on your batteries. The MPPT charger-controller extends battery life immensely, and must be used. Now you can probably see why we prefer on-grid support. That being said, we totally understand that folks like to get away from people, the government, utility companies etc. It is not a problem helping you with whatever objectives you have in mind, it just simply costs more to live off-grid generally speaking, and is a lot more hassle and sacrifice, BUT with the generous tax credits and no more power bills every month, it can actually work out better. We just built a home in Hawaiian acres, and it was going to cost $17k for our customer to install 3 poles, wire their home and pay HELCO to hook them up. Their 2-3k watt system is about $10k for the hardware, and about $2k additional to install the pv hardware etc, but with a 65% tax credit, they will save about $6k overall vs on grid, and no more power bills until they change batteries in about 10 years, so that is not such a bad deal! It can be done, and it can be a fairly comfortable life if you plan it out nicely and thoroughly.
There is no free lunch in life, so being off-grid requires more thought and effort, with the payoff being freedom from the utility company and their ever-increasing cost for energy. We can help you greatly by looking at your unique situation and advising you accordingly. We do our best to minimize your stress as much as humanly possible. Cost is always part of any living solution, and there is no way around spending money to make anything happen.
There are companies that make cool little units from highly modified automobile alternators that are around $400 more or less. You can purchase them one at a time and assess your needs as you go. Again, we cannot over emphasize the beauty of having power at night to keep that arsenal at a healthy voltage without running that generator. If you are in the Puna jungle, you most likely do not have enough wind to warrant the purchase. Folks in Hamakua, Kohala, South Point etc generally have tons of wind. There are a lot of things to consider when searching for that new location to build at. If that magic place is totally off-grid, go for it, and plan intelligently!
Other helpful info
LED lighting is very energy efficient and reasonably priced, making it an obvious choice for those off-grid. Every light source has its own feel and nature, so living on-grid does give you more options when it comes to lighting. Download an energy inventory form online and carefully evaluate the power consumption of your lighting and everything you use in your home. You will be greatly surprised at how much more you use vs what you think you use, and you will forever change the way you look at how you live your life. It is a great first step to becoming more efficient and green.
Let us know if we can help you sort thru your options, design and/or build your home, design and build your alternative energy system, water system, septic system etc, give us a ring or email us. We hope this information has been helpful to you!