To see as much of the world as we can,
Using the smallest carbon footprint we can,
Spending the least amount of money we can,
Making as many friends we can.

Team Red Cruising

Getting off the Grid

The Commodore Says "We need reduce our dependence on diesel fuel." How do we cut our dependence on petroleum? How creative do we have to be? Are we going to revert to cave-dwelling?

The diesel auxiliary ("Mr. Lehman") for moving the boat is difficult to restrict. We can try to sail more and motor less. But it's hard to eliminate all motoring. Tight quarters. Docks. Slips. That kind of thing means we'll always burn some diesel.

The electrical system is charged by the diesel engine. This is something we can (and should) control. This requires some creativity. How much? Where do we apply it?

  1. Reduce Demand. Replace all incandescent and fluorescent fixtures with LED's. This is about half done. We have five lighting fixtures to replace with something like these LED Berth Lights. [We could replace bulbs in the existing fixtures, but the existing fixtures aren't worth preserving.] We have a detailed energy budget in a big spreadsheet.

  2. Improve Supply. This means non-diesel battery charging as well as more efficient battery charging. There are several parts to this: solar, wind and towed.

There are a bunch of steps to improving our power supply. We Got the Power shows the upgrades to the alternator to make it more efficient.

We've also upgraded our shore power charging. The shore power charger doesn't get us off the grid. It's important to note that shore-based bulk power production is relatively efficient. It's far from good, but it's quite a bit better than the low-rent power production on Red Ranger. High-voltage AC systems are less inefficient than low-voltage DC.

Decisions Decisions

The next step is to add solar. This involves a lot of hand-wringing. A lot.

There are four places we can install solar panels. That's just one of the problems we need to solve.

  • Directly on the deck using "semi-flexible" panels. These are very simple to install.

  • Foredeck. Two 18W long, narrow panels plus two more 18W squarish panels. 72W total.

  • Afterdeck. Maybe we can pack four SunWize SC12's for a total of 48W.

  • Mounted on stanchions or supports.

  • Bimini top.

  • Taffrail or lifeline stanchions.

Each location is a tradeoff. The on-deck mounting means they have to be robust and low-profile: they'll be underfoot. The stanchion or support mounting means a fair amount of engineering is required to create (or modify) the boat to support the heavy panels.

In addition to "where?" there's the question of "how much?" Our detailed energy budget (at anchor) is almost 80Ah per day. That means that two days will drain the batteries to 65% of charge. A third day would be over 50% discharge. We need to invest diesel fuel in recharging the batteries. This means running the engine for two hours (or more) every third day. [At ⅔ gallon per day, and $4 per gallon, think $2.66 per day for power.]

The issue is getting 80 Ah (1.077 kWhr) into the batteries each day.

The worst-case insolation in the Bahamas is \(4.62\:\text{kWhr}/\text{m}^2\). See Weather Underground's solar calculator. Panels are only about 15% efficient, so we are looking at \(0.693 \: \text{kWhr}/\text{m}^2\) of usable power pouring down from the sun.

\[ \frac{79.8 \times 13.5}{4.62 \times 0.15} = \frac{1.077}{0.693} = 1.55 \]

This means \(1.55 \: \text{m}^2\) of panels; about 17 sq. ft. A panels' sales pitch usually emphasizes the watts of power produced. Based on the common assumption of 10W/sq. ft., we need to install panels with a total output of 170W.

The various deck-mounted locations may get us to 120W. That's 70% off the grid while at anchor. After a week, we'd need to run the engine for three hours to replace 168 Ah. [At $4 per gallon, think $1.72 per day.]

Total Independence

It appears that we're just getting started. We have to continue to add yet more solar panels. Where do we stop? What's the upper limit?

Extended cruising means running our energy-intensive autopilot, Mr. Benmar, 24 hours each day. This means that we would need 350W of panels to cover the 166Ah budget. Without those panels, we have to run the engine almost 1.5 hr every day to keep up with the (worst case) autopilot energy demand. [Think $6 per day to move the boat.]

The bimini top offers over 36 sq. ft. of space. (\(3.34 \: \text{m}^2\)) But just two of the large-ish, 85W panels is about 60 pounds of weight on a bimini that seems designed to hold up nothing more than wet fabric. We'd have to rebuild the bimini. Also, there's not much clearance between boom and bimini top.

Or. We could mount additional large (130W each) panels on a set of new stanchions on the aft deck, parallel with the lifelines. The Whitby Forum Discussion has pictures of the Gaia II installation. These large panels weigh about 60 pounds.

Or. We could get a towed generator. A DuoGen can produce—perhaps—8A of power while sailing at 6kn. The boat consumes about 7A under way. Total energy independence. This is about as complex as the bimini rebuild or adding several new stanchions. And it covers the worst-case very nicely.

Political Rant

What we're learning on Red Ranger is that energy independence involves some investment.

We've had a boater who was a former power system engineer tell us—flat out, no quibbling—that "alternative" energy sources are simply a waste of time and money. Petrochemical (i.e. diesel) is the only effective solution.

"Why?" we asked.

The response was clear: demand management won't work. "People won't restrict their energy use."

If someone who used to run public power systems has this attitude, that seems like it's going to limit their creativity. Since large public utilities can afford lobbyists and extravagant campaign contributions, their overwhelmingly negative voice seems to drown out the voices of voters. This negativity means that oil exploration is still subsidized by tax dollars, while non-oil energy development is debated.

Red Ranger is certainly interested in improving our energy infrastructure (i.e. solar, wind, and demand management) to reduce our dependence on petro-chemicals. We don't think we're alone. The marina seems to be full of like-minded folks. Perhaps there are people outside the marina who think that demand management and "alternative" (non-coal, non-oil) power sources are a good idea.

It appears that we lack the lobbying and campaign contribution budget to make our voice heard.

So, we'll start by taking action to reduce our dependence on petroleum-based energy. Maybe someone else can take action to eliminate corporate campaign funding so that our voices are heard.