Are You Thinking of Going Off-grid?

First off, before you dive into this whitepaper, ask yourself the following questions and depending on your answer it might save you a lot of reading that could be irrelevant to you… time is precious, use it wisely.

It’s also important to note that the views expressed here are our sentiments and are endorsed only by our academic and field experiences, i.e. our interpretations do not necessarily represent the views of our clients, distributors nor providers.  In addition, we are in Belize, Central America, and we use the same single split-phase power grid configuration as our bigger neighbours Mexico, USA and Canada. Therefore, our examples might be more applicable to this side of the hemisphere.

Having read and understood the above, our first question is:

Are you thinking you will save a ton of money disconnecting from the grid?  Depending where you live, the cost of living off-grid as compared to being on-grid is three times higher, if not more.  So the answer here is easy: “absolutely not”.  This might be where you jump off this boat and go for a cup of tea or beer.  However, if you want to hear a few reasons supporting our answer you might want to read the next few paragraphs.

The most important reasons why it’s so costly to live off-grid are not only the cost of equipment, but in fact that our “energy” uses bad habits and its lack of understanding.  You might be a college graduate with perhaps a post degree in some science, but that is not the case in point here. Our point is that we have become consumed by everyday life and no longer have the time to stop and analyse how our homes are powered or where the resource comes from.  Let’s take a quick look.

In modern society, Water and Power are the most important resources in our homes.  Not rocket science so far, but how much does it cost to generate or manipulate these resources is the question.  Let’s take Power and assign some $$ figures so we can begin getting some essence from this blah, blah…

Before we can jump in to an example, we need to establish an energy consumption baseline; let’s assume that the average US household uses about 30KWH per day, while Europe uses half of that and rest of the world about one fourth of that.  For the sake of time let us do a little math with this 30KWH target. We will also use $0.12/KWH as energy cost.  Therefore, 30 X 0.12 = $3.60/day ($108/mo. or $1,300/yr.). FYI, here in Belize we pay $0.49BZD, which equates to nearly $0.25USD/KWH.

Researching for present “residential” solar installation costs you’ll probably come up with an average of about $3/watt installed.  So how many watts do we need to get our 30KWH? That should be our first real question. Well, divide 30KWH by 5Hrs, which is hours of average solar irradiance in Belize; you should come up with 6KW.  Now, simply multiply that number times your $3/watt and should get a number like $18,000. Let’s call it $20K because it’s easier to remember and there are insurances, cost of ownership and other misc. which we want to omit for the sake of moving on.

If you’re still reading, we’re at the conclusion of this energy mystery, and you don’t have to be a financial guru to know that all we need to do now is divide our total project investment by our yearly power bill cost to come up with how many years it will take recover our investment (IRR)… ready??? 

 $20,000 / $1,300 = 15yrs.

Of course this sounds like a very pessimistic conclusion to our cause and industry, and questions like what about State refunds and other incentives will possibly surface; but we simply do not know what those perks are, so you will have to factor those in.  We do know that here in Belize, as do other parts of the world, we have zero such incentives. It is our goal to inform you as realistically as possible and not disguise any known info. Our client’s database is filled with “excellent” clients and we attribute that to properly-informed folks, most of which are now also friends.  Quite honestly, if you feel a bit uneasy about what you have read so far please stop here, the next paragraph is where reality takes it home.

If you’re still reading, we have to thank you, and promise that we will get you through the rest a lot quicker so you can get on with your day.  The truth is we haven’t answered the catch phrase you begun reading this whitepaper for “are you thinking of going off-grid?” So far, we have referred to a “Grid-tie system” and NOT an “Off-grid” system; which is a lot more complex with batteries for storage and other switchgear that will inevitably double your investment.  The good news is that we’re here to ensure you do not have to double your investment due to unknowns, and we hope to create a clearer understanding of what it means to comfortably live off-grid by simply changing some bad habits and most importantly, some “bad” household appliances.

Here’s a short-list of the biggest energy hogs in a regular on-grid home:

• Electric range/toaster (5KW)
• Air conditioners, central (5KW)
• Electric clothes dryer (5KW)
• Electric water heater (3KW)
• Dishwasher (2kW)

The list goes on with microwaves, hairdryers, coffeemakers, etc… But those are usually items that can be driven by your system and we can deal with, as long as we understand their presence.

We’ll try to keep the math out of the way and just put things into context as plainly as possible.  A quick glance at the short culprits list, shows us that they will draw about 20KW of instantaneous power, multiplied by the hours of use, let’s say one hour, and that’s 20KWH of our 30KWH average energy consumption.

As we briefly think of our system design, it’s obvious we need to remove some of these items if we are to end up with a cost-effective off-grid setup.  Unless you have a bottomless pocket, I would advise you to read the following recommendations. Don’t worry, we won’t have you cooking in a firewood hut, taking cold showers nor hanging up your draws all over your yard.  ☺

The solution is to change the Range, Clothes Dryer and Water Heater to LP gas (LPG) units, which are a heck more efficient at transforming energy into heat.   This may or may not be something new to you, depending in the State or country you live in. LPG appliances are readily available in most parts of the globe and here in Belize, the LPG cost is somewhat regulated.

Air conditioners are not readily available in LPG, but they are available in high-efficiency mini-split units, where each room that requires conditioning is equipped with its own small unit so that you are only cooling portions of the house as required.  Generally speaking, there’s no need to be cooling bedrooms during day hours nor living rooms during night hours.

Now that we have identified appliances that should lower our off-grid system cost in half or more, it’s time to identify our bad habits or lack of resource understanding.

Water is perhaps the least thought of resource when we’re on-grid; we do not know where it comes from nor how it achieves the pressure that it has in our plumbing, about 45PSI.  If you’re considering to go off-grid you will need to know where your water is going to come from. Simply because no power usually means no potable water either. Therefore, the obvious might be to dig a well, collect rainwater, tap into a spring, etc.

Let’s assume you dug a well and you now have water.  Now ask yourself, how does it get from there to my home?  You will require a well pump, correct? Which will also require “Power”.  And depending on how much water you use, or waste, that’s how much power it will consume.  If you collected rain water, you will need a “water booster or jet-pump”, to get the stagnant water from your tanks or cistern and pressurize it to 45PSI. The water booster/jet-pump will also require power and will be an additional investment.  Therefore, taking an hour long shower, using water-wasteful appliances such as dishwashers not only means throwing water away but burning costly power.

If you’ve read this much and don’t have a headache, you’re ready to look at sections like “Designing Your Own Solar Off-grid System” and other more technical whitepapers.  Or you might just be ready to send us an email or give us a call with more confidence in the matter, with the understanding that we’re not here to sell you anything you don’t need.  We are here to advise you, to make sure your $$ are properly invested, and hopefully to make “a new friend” ☺ 

Take care and may God bless you and yours!!!

The PSE Team.

https://www.prosolarltd.com/ Email us info.prosolar@gmail.com Tel: 501-822-2216