OT - Extremely long! - Energy Audit and budget

[skipgundlach]

OT - Extremely long! - Energy Audit and budget


This was first written in Charleston, in late September, 2007, at
a dock, which skews some of the wind information (and
ventilation, too, as the boat doesn't face the wind all the
time). Since then we've let this information "cook" a bit in
order to get more of a "real-world" handle on what our usages
would be. We found that we used more of some, and less of
others, than expected.

We've also made some basic changes after our experiences, chief
among them ditching a ravenous laptop foisted on us by the vendor
of our navigation package (Cap'n, laptop, and evaluation programs
of an entire suite of other programs for communications and
weather) as being "perfect for the environment we're in" - his
standard package at the boat shows. In addition to every known
bell and whistle, it's got an external 3.5" floppy drive,
built-in RS232 for Pactor, and even a television tuner, complete
with remote - but the DVD player and TV tuner can't be activated
by themselves - the desktop chipset, with its attendant power and
heat load, along with the hard drive, has to run, as well. Maybe
on a trawler, with its mostly 110V systems, or a boat with
umpteen AC devices requiring a constant genset, rather than the
inverter we use, but 13A of inverter use to run the computers is
more than unacceptable. We are replacing it with a 3A 12V unit
and a 3A large screen monitor, which is also our entertainment
center, and so we're willing to accept even that relatively large
power demand. (The large screen uses more power, leading to a
higher level of power use than might be the case with a much
smaller one. However, it's our entertainment center screen as
well, limiting us to only one separate screen.) If we find that
to be unacceptable, the other laptop, only 3.5A, but with its
attendant much smaller screen and hard drive, may become our
navigation unit (we use MaxSea, and occasionally the Cap'n, as
backup to our paper charts and chartplotter if the sea state
permits, for very close
navigation).

On the flip side, we have found that cheapo WalMart automotive
fans have a surprisingly low draw, but put out a great amount of
air movement as compared to either Hella or the other, AC, fans
we had been using. So, we're switching over where we used to
have AC fans, making a very significant difference in the
forecasted nightly load, should we be in hot, calm, waters. We
have found, however, at anchor, in nearly any (steady) breeze, we
don't need fans, as was our original expectation.

Here's what we originally wrote in September 2007 - and I've
added editorial comments where there have been changes or
revelations:


We recently did an energy audit of everything we could remember
to check aboard. It was a hot and windless night, so we were a
bit overcome and missed some obvious stuff like computers with
the screens down (for all applications not requiring looking at
the screen, such as movies [separate screen], satellite weather
reception [sound card only], e.g.), and the red LED lamp at the
Nav, but those are relatively insignificant in setting up our
electrical budget.

- - Editor's Note PS: Our new computer won't require the screen
for satellite weather, and the internet phone won't require even
a computer - just the router at the top of the mast, and the
Vonage router below. So, in the times we watch a movie, the net
difference will be more than 7A (14AH for the typical movie) than
our original prediction, and in ordinary communications times,
the same. However, the overhead to snatch satellite pictures
will drop by even more due to no screen. - -

We then set up scenarios of anticipated usage types, in order to
see not only how much we were likely to use, but identify any
obvious potential energy savings. In areas where we might have
more than one of a type (salt water vs fresh pump, e.g.), we just
showed the higher load. In items where there might be only very
occasional (vs regular) use, such as spreader and foredeck lights
(single breaker, only for night sail change), or microwave for a
minute to warm coffee gone cold, we neglected those in our
scenarios.

Lydia's in the middle of hot flashes, so fans are very important,
but as I expected and warned at the time of purchase, the AC fans
are huge energy hogs. Changing just those out for 12V, whether
hyper efficient (Hotwire Port Fans or the like) or merely notably
less draw (Hella or the equivalent) will change the at-rest load
very substantially. The problem, of course, is that they don't
move much air as compared to the AC fans. We're hopeful that
being at anchor (vs our current-as-written at-the-dock situation)
will provide enough of a breeze that it will be less of an issue,
and we'll not use the AC fans, or only the smaller ones.
However, likely we'll replace them, in any event...

- - Editorial PS to this composition time; we've been at anchor
for many days' time and we've not needed fans - but have bought
cheapo WalMart automotive ones, as they move a lot of air for the
0.5A, during unusual times... - -

Computers will be used on an occasional, regular (not left
running or even resting) basis (typical ~2H/day), but all the
external drives will be accessed only as needed (never powered up
otherwise). All of these loads are controlled over power
centers, 5 individually switchable sources in a single unit (two
of them, to handle the number of drives and computer-related
items, as well as charging items such as handhelds, phone
handsets, spotlight, etc.) - none are operating unless in actual
use minimizing power draw. Music will be moved from HD to chip,
which will then be used in the sound system for distribution,
thus not only minimizing power demands but also limiting rotating
parts' time of operation (no CDs or computers required to do the
music once transferred).

- - Ed. Note PS The hard drives are now converted to 12V, saving
that 120VAC/12VDC conversion inefficiency, as part of the
computer redo. That's also led to our needing only one power
center, saving the (admittedly very small) resting overhead. - -

Anectdotal evidence (many user reports) suggests that solar will
produce, on average, 25% low, 33% typical and up to 50% high of
watts to AH per day. User reports also suggest that the KISS wind
generator, in moderately breezy conditions, will produce
90AH/day. Of course, if it's like it currently is here, that
will drop precipitously. On the other hand, while sailing, or in
any other windy circumstance, the output rises substantially. At
15k wind we get about 12A, 20k=~15-20A, and 25k=25-30A. So, the
wind component at 90AH/day (under 4A constant average) sounds
very reasonable. A view of the svhotwire.com, the US
distributor, or the KISS manufacturer's, website will give more
detailed info on output from the KISS.

One user reports:
"Early on before installing the KISS wind generator and instead
was using my two siemens panels I kept a log which in the end
spoke to the daily gain. For the most part I found that daily
output (week in, week out) consistently ended up at an average
equal to or less than four times the rated output of the panel(s)

I should add that the panels were mounted stationary without
gimbals.

Fair winds, calm seas,

Capt. Bruce Gregory, IP 32-84 Morning Star
USCG Licensed Master of Power/Sail/Towing"

That would suggest an overall average output, in our system, of
~370 (our solar panels' total)x4 (1480) watts daily; if one can
reasonably use a 12 hour maximum day for solar generation, you
can see an average of over 120 watts per hour - which is right in
line with my expectations. Of note is that this particular
poster is in relatively northern waters on the US East coast,
which is not an ideal solar environment due to the sun angle.

Another user currently with only 2 120w panels reports that
despite heavy usage of two computers (internet university for 2
people) and all the usual bells and whistles of a 12V
refrigerator-equipped cruising boat, they run the auxiliary
engine once every three days for a short time to top up the
batteries, and that without the computers, it keeps up easily.
That's in a relatively northern latitude in late summer.

So, I think it reasonable to expect our projected 90-180AH, with
120AH, daily, as average output from our panels. KISS is another
matter, as in the same latitude as the above, we're not seeing
much wind generation. There's always the Honda, and hot water
comes immediately with the aux Perkins, so if we have to move, or
even just fire it up for a bit, we are usually supplied with not
only hot water but another hundred or so AH.

- - ED. Note PS: We decided that 15 minutes of Honda time (see
below for expansion on the Honda), for resistor powered hot
water, was far more efficient than starting and warming up (and
not loading up, not good for the aux) the Perkins, in both fuel
and life-costs terms, for at-anchor times. Of course, if we have
to be moving with the auxiliary, anyway, we'll have the hot water
in spades. Of course, except for extreme circumstances where we
have to use all the output of the Honda (microwave, heat gun,
water heater) at the same time as a low-battery situation, or if
we're under way anyway, the Honda will charge at the full 40A in
the shorepower circuit when not doing the hot water routine. As
the charger, of course, also tapers as the overall charge state
grows, we take advantage of times running the Honda to recharge
any AC-powered devices, such as the rechargeable batteries for
flashlights and the like, the telephone handsets, and to run any
"discretionary" AC devices at that time. If we need to vacuum,
or defrost the reefer (well, technically, the freezer), e.g.,
those are done during times we run the Honda. - -

Overall, we expect a sufficient power input, just sitting, long
term, as no instruments are being used, and minimal lights (no
incandescent running lights or the like required at anchor). Any
motoring very substantially increases that output, overcoming any
shortages in poor wind/solar situations, and sailing, by the
nature of the wind, will have a high wind generation component.
Over time, if we can keep our no-alternator average usage below
150AH/Day (allowing for inefficiency in transfer of amps back
into the battery), we believe we should be in fine shape.

Managing these sources and loads, we have:

We have a TriMetric 2020 monitor, by Bogart Engineering, which
provides a lot of information. Volts, amps in or out, state of
charge in percentage terms are all front-and-center. Menus allow
time from equalization, AH left, current state of AH up or down
in numerical terms, time from and what is low and high (two
separate measures), and so on, all in digits and tenths.

Our controller for the KISS wind generator (in addition to the
on/off control of the generator itself) is a Xantrex 40A unit.
When it's piping outside, we can get close to 30A before the
internal controls shut down, but it doesn't start producing
meaningful amps until ~15knots (designed for the Caribbean
market). It's whisper quiet in our setup; YMMV dependent on how
well you balance the blades. At full charge, that controller
diverts to a heat strip setup, required because our water heater
wouldn't accept the dual voltage unit where we used to send
overcharging before we replaced the water heater. We have not
yet installed (because we can't find where we stored them) an
incandescent monitor lamp so that if that's happening we can
hurry and turn on charging loads for AC devices, taking advantage
of the overstock of amps (see above about power centers, allowing
us to select those loads), or make that the time to use
optional-time-scheduled heavy-draw units, such as computers
and/or monitors.

- - Ed. Note: The Xantrex took a dump, and we've found our usage
to be high enough that, as we'd unlikely ever actually get to
equalize our large battery bank, we have set it to go directly to
charge all the time, full time. We disconnected the heat strip,
as well and so, while we've not yet installed the indicator
light, if we ever get nervous about overcharging, we'll install a
new controller and the indicator light. - -

Our controller for the 370W of high-voltage Solar is a Blue Sky
6024H MPPT, which provides as much as 30% more than the rated
values of our panels. At 9AM in Charleston, we typically show
12-15A, and at best, sometimes as much as 25A in mid-day. That
controller just turns off the load (open-circuits the panels, I
think is what's happening) when they're full, and then controls
the output to a floating state, cycling on and off briefly. It
also has an equalizer button, but with a 750AH battery bank, it's
unlikely we'll ever see enough amperage to actually accomplish
that, even connected to shore power, as (or, at least I'm unaware
of any such feature) we can't override the internal regulator in
the alternator to push the additional amps needed to equalize.
However, see "battery conditioner" below...

- - Ed. Note: In Miami at anchor in High winter, we see 20-25A
solar at mid-day (much less than we'd expect in the Caribbean,
with the sun 20-50 degrees higher in the sky), and as the
northers come through, we typically see as much as 25-30A in
peaks, but 10-15A routinely on the KISS. Frequently, with two
computers (see above about needed amps for those, as the new
one's not yet installed) running all day as we worked on our
final medical issues (Cobra just ended), did our taxes and
wrapped up the last of the OUPV documentation for both of us,
lights, movies, refrigeration, radios and the like, we'd start
and end the day and night with the batteries full on sunny days
with the wind blowing. However, in calm days, with overcast
limiting the solar to 5-10 at best, typically we'd run the Honda
(more below) ~6 hours (a smart-speed 1-gallon tankful), feeding
our AC devices, but keeping the batteries up. Of course, the next
paragraph was written before these Ed.Notes :{)) - -

Finally, in dire circumstances, we have a Honda eu2000i genset.
Its intended use is in third-world or offshore power tools
source, our hookah rig, and, if needed, connected through our
shorepower adapter to the 110VAC aboard, powering any and all
loads AC, including the shore power battery charger. The Honda
will drive the 40A shorepower charger at full blast while
supplementing any wind and solar, and still have other power
available for other AC loads aboard, freeing the battery from
those loads at those (expected to be nearly never) times. As the
genset's full-power use is 4 hours/gallon, that will be an
economical modus for additional charging as compared to running
the diesel at (high idle) 0.6 gallon/hour. And, as another
correspondent has noted, as inexpensive as they are, just running
them until they die, and then buying another is a viable plan
when compared to single-purpose (charging) auxiliary operation.

We also have a battery conditioner attached - it uses the
battery's own power to pulse, helping prevent/minimize
sulphation. The very long-cycle charge regime of the solar and
wind has meant that we very rarely see less than "full" on the
monitor. Making sure we see above 13V nearly all the time we're
not running huge loads is the bigger deal. However, initial
usage has suggested we may be in for new batteries. They were a
bit abused in the early days, not knowing of our shorepower
charger difficulties, and during sailing/motoring, not knowing of
our alternator's (well, actually, the line from the keyswitch to
the alternator; the alternators are fine) difficulties and being
profligate in our energy usage while presumed to be fully
supplied. In any case, they're over 2 years old, so their life
cycle is under way. I'd sure rather not have to buy new ones,
but I think I'd prefer that, and a functional and efficient
750-800AH supply, to having to run a genset or the motor to
recover a very low AH withdrawal (presuming our wind and solar to
be adequate to the task)...


In any event, these are the items and their loads, in amps, in
our system, followed by the 5 likely scenarios.

Resting voltage: 13.2-13.3

DC items:

Reefer, full blast 4.7
Fuel Polisher .8
Back Porch Light .6
Running Lights 5.1
Steaming Light .8
Spreader and Foredeck Lights 6.7
Anchor Light .4
Tricolor .4

Autopilot (standby) .3
Autopilot (full power constant 5A, worst case estimate under way,
average) 3
Indicator lights all switches (background) .3
Depth finder .3
Second depthfinder .2
Helm GPS .1
Compass light .2
Small engine room blower (hot air) 3.0
Large Bilge blower (and more heat removal) 6.0
Cockpit white light .1
Cockpit red LED rope .1
Cockpit VHF (standby) .2
Cockpit VHF (Transmit) 3.0
Radios (all, Nav) switch load .1
Satellite (weather images) radio .1
AM/FM .3
HF (standby) 1.0
HF (Tx - low) 2.2
HF (Tx - Med) 2.2
HF (Tx - high) 2.2
VHF (Standby) .3
VHF (Tx) 2.0
GPS .2
Radar alone 3.0
Charts alone 1.7
Charts and Radar 3.0

Forward Shower Pump .9
Aft Shower Pump 3.0
Fresh Water Pump 5.0
Salt Water Pump 3.0

Kitchen red LED rope .1
Kitchen amber LED rope .3
Galley Fluorescent .4
Freezer Fluorescent .4
Cell Phone charger .3
Propane solenoid .5

Forward Head light (1) 1.0
Forward Head light (2) 2.0
Vee Red LED rope .4
Vee Amber LED rope .5
Vee Hella low .1
Vee Hella high .4
Vee (reading) LED .1

Salon (reading) LED .1
Salon (reading) LED .1
Salon closet LED rope .5
12V "Box" fan (low) .8
12V "Box" fan (medium) 1.6
12V "Box" fan (high) 2.8
WalMart Automotive fan .5
WalMart Automotive fan .5
WalMart Automotive fan .5
WalMart Automotive fan .5

Aft head "red" .3
Aft head "white" .3
Aft Hella low .1
Aft Hella high .2
Aft closet LED rope .4
Aft fluorescent .3
Aft (reading) LED .1
Aft (reading) LED .1

Workbench red LED rope .2
Workbench (4-foot) fluorescent 1.4
Workbench hardware bins lid red LED rope .4
Workbench incandescent 1.4 (never used due to fluorescent
brilliance)
Workbench closet white plus LED rope 1.0
Walkthrough closet LED rope .4

ER double fluorescent light 3.2
Aft bilge pump 4.7
Forward bilge pump 1.0
Auto (electronic) bilge pump .5
Inverter overhead .1

Anchor and start loads unknown but insignificant due to engine
running replacing amps at time of use

110VAC items (through inverter, 12V amps shown)

Inverter background .1
Drop Light, Fluorescent 2.0
Toothbrush 1 .1
Toothbrush 2 .1
Hair Dryer 102.5
Microwave 102.0
Small fan .8
Small fan .8
Large fan (low) 1.6
Large fan (high) 2.2

Vonage handset charger .2
Vonage handset charger .2
Vonage router .3
POE 12V/data injector/WiFi Bridge .3
"WallWart" Power Supply (inferred router) .4
"Notebook" computer (SeaTech) standby (full battery, but
connected) .4
"Notebook" computer (SeaTech) (operating) 9.6
"Landside Laptop" (Acer) standby (full battery, but connected) .1
"Landside Laptop" (Acer) operating 3.5
Note: unknown without screen lighting, significant - applications
include satellite image capture, movie watching on separate
screen, downloads, uploads, etc. - We'll use full power to be
conservative in calculation
External Monitor LCD (Movies) 2.9
Backup Drive 1.1
Movie Drive .6
Music Drive .9
500G drive .6
Printer, standby .1
Printer, printing 61.0

Rechargeable Battery (camera, flashlights, etc.) charger .3
Sewing Machine 4.7
"Stinger" mini shop vac 25.0

Assumptions:
* Reefer/freezer box as built requires 4000BTU/Day (per
engineering specs on 3 different reefer design internet sites) in
tropics, plus lost cold for openings. Design sites assume
opening both compartments, but we'll add for heavy use, and the
inevitable front-opening (reefer) air exchange. Use 5000BTU to
calculate daily load. Danfoss 50 can dump 750BTU/hour. Frigoboat
Smart Speed Controller ("SSC") limits high power runs but runs
more time (objective 50 minute runs per hour at appropriate
speed); assume one hour full speed running per 750BTU removal
4.7A=4.7AH/750BTU). Anticipated daily load 6.66 hours, 31.3AH.
Add 25% for addition of warm items; 39.1 - day in, day out. With
all the indicator lights lit (24H =7.2AH total) in the control
panel as a constant load, call it 40AH reefer and disregard
control panel lights as a separate item. Also, at anchor, most
of the control panel lights will be out due to no instruments in
use. Likely smaller cooling load in a non-tropical environment
will also operate to reduce the power used..

- - ED. Note: Richard Kollmann, noted marine refrigeration author
and consultant, has speculated that "real-world" usage is as much
as double the heat load as the industry standard calculations
would have it. Based on conversations with him, I've doubled my
usage calculation for my end results, so our expected
refrigeration load is more like 80AH in the tropics. Our
"real-world" experience showed a markedly lower run time and/or
speed (yielding lower consumption during running) in cooler
waters and air temps, however. As well, recent surveys of some of
the mailing lists to which I subscribe had typical similar-sized
boxes, but with considerably less insulation, reporting daily
amp hours of well under 60, and mostly under 40, so YMMV :{))
We're anticipating that our much higher generation capacity in
the tropics would offset any such increase in loads caused by
refrigeration. - -

* Autopilot requires high current but not measurable without
constant running. Use overall average of 3A, 12H total=36AH to
start.

* Scenarios show charging times for appliances in each case but
realities are that when we have excess power, we'll do all the
charging of small appliances. Insignificant charge loads make
those of no great moment in any case, whichever way they're done.

* Occasional, high volume (printer, microwave, heat gun [tools
not shown but assumed same 1500W load of 120A as hair dryer],
shop vac) use will be monitored and accounted for in charging
regime on those demand times

Scenarios:

1) At anchor, 24 hours

Anchor Light (12H) 4.8A
Red Cockpit LED (12H) 1.2
Reefer (24H) 40A
Inverter background (24H) 2.4A
Toothbrush chargers (1H) .2A
Overnight Fans (9H, 2 fans) 33.4A
Red lights below (12H) 6A
Download movie (small computer, movie drive .5H) 2A
Movie (small computer, LCD screen 2H, Large Fan 2H) 17.2
2 popcorns (10 minutes microwave 0.16H) 19.2
Reading (aft fluorescent 1H) .4A
Chart planning (cap'n/computer, chartplotter 1H) 5.2
Weather (Hamtronics, computer 2H) 7.2
Weather (VHF 1H) .3
Checkins (HFRx/Tx 1H/.1H) 1.3A
Propane (1H) .5A
2 showers (20 minutes water .33H, 10 minutes pump .16H) 2A
Misc Fresh Water (.25H) 1.25A
Cell Phone Charger (1H) .3A
Vonage Phones (POE, Base 16H) 9.6A
Vonage Chargers (2H) .8A
Internet checkin (computer, 2H) 7A
Total 161.05AH Solar and Wind
- Days without movies, subtract 36.4AH ( revised Total 124.65AH)
- if out of wifi range (no Vonage, no internet checkin), subtract
17.4AH (revised Total 143.65AH)
(Ed. Note: WalMart fans = 9AH, new computer for movies total
12AH, total over 50AH savings for both)
Power source: Wind and Solar, Honda if long-term use requires
(extended calm, cloudy period)

2) Cruising, sail, day 12 hours

Reefer (12H) 20A
Inverter background (12H) 1.2A
Toothbrush chargers (.5H) .1A
Chart/radar (chartplotter 12H) 36A
Instruments (GPS, Fishfinder, wind, depth 12H) 13.2A
Autopilot (12H) 36A
weather (Hamtronics, computer .5H) 1.8A
(VHF 12H) 3.6A
Misc Fresh Water (.125H) .6A
(Disregard anchoring as motor will be running)
Total 112.5AH
Power Source : 1H maneuver and anchor ~60AH bulk charge if needed
(wind and solar still operate under way)


3) Cruising, sail, night 12 hours

Reefer (12H) 20A
Inverter background (12H) 1.2A
Toothbrush chargers (.5H) .1A
Chart/radar (chartplotter 12H) 36A
Tricolor (12H) 4.8A
Instruments (GPS, Fishfinder, wind, depth 12H) 13.2A
Autopilot (12H) 36A
Compass Light (12H) 2.4A
Red lights below (12H) 6A
Weather (Hamtronics, computer .5H) 1.8A
VHF (12H) 3.6A
Misc Fresh Water (.125H) .6A
Overnight Fan (9H, 1 fans) 16.7A
Reading (aft fluorescent 1H) .4A
Checkins (HFRx/Tx 1H/.1H) 1.3A
Propane (1H) .5A
2 showers (20 minutes water .33H, 10 minutes pump .16H) 2A
(Disregard anchoring as motor will be running)
Total 146.6AH
Power Source : 1H maneuver and anchor ~60AH bulk charge if needed
(wind still operates under way)

4) Cruising, motor, Day 12 hours

Reefer (12H) 20A
Inverter background (12H) 1.2A
Toothbrush chargers (.5H) .1A
Chart/radar (chartplotter 12H) 36A
Instruments (GPS, Fishfinder, wind, depth 12H) 13.2A
Autopilot (12H) 36A
Weather (Hamtronics, computer .5H) 1.8A
VHF (12H) 3.6A
Misc Fresh Water (.125H) .6A
(Disregard anchoring as motor will be running)
Total 112.5AH
Power Source: Up to 1KAH available with engine running in that
time, plus wind and solar

5) Cruising, motor, night 12 hours

Reefer (12H) 20A
Chart/radar (chartplotter+radar 12H) 36A
Nav and Masthead Lights (12H) 70.8A
Engine Blowers (12H) 108A
Instruments (GPS, Fishfinder, wind, depth 12H) 13.2A
Autopilot (12H) 36A
Compass Light (12H) 2.4
Red lights below (12H) 6A
Weather (Hamtronics, computer .5H) 1.8A
VHF (12H) 3.6A
Misc Fresh Water (.125H) .6A
Inverter background (12H) 1.2A
Toothbrush chargers (.5H) .1A
Overnight Fan (9H, 1 fans) 16.7A
Reading (aft fluorescent 1H) .4A
Checkins (HF 1H/.1H) 1.3A
Propane (1H) .5A
2 showers (20 minutes water .33H, 10 minutes pump .16H) 2A
(Disregard anchoring as motor will be running)
Total 304.6AH
Power Source: Up to 1KAH available with engine running in that
time, plus wind

- - Ed. Note: For our original configuration, Caribbean use, we
would expect something on the average of 120 to 180 AH/day solar,
worst to best, and 120 to 600 AH/day wind, though the "high" wind
picture would have to be a sustained high-winds environment, such
as, perhaps, the Christmas winds, blowing at 25 or higher 24/7.
If we found that situation (continuous high wind), likely we'd
turn the KISS off during the day, or perhaps entirely, depending
on our actual battery state. In any event, we expect that the
current configuration would work well in the designed use.

However, on the East Coast, with its relatively lighter winds,
and lower-angle sun, we've found that it would require both more
power management than we have been exercising and more power
input than is (reliably) available from the sun and wind. For
those considering doing what we're doing at the moment (cruising
the East Coast and perhaps the Bahamas), for their cruising
experience, more solar is most likely the answer. When I
designed our system, unfortunately, I didn't "think outside the
box," and so overlooked an opportunity to have substantially more
solar area than we do currently, possible by different placement
of larger panels. If we find that we are running the Honda once
we get to the Caribbean, likely I'll redo the solar array to take
up the slack. Back to my original writings: - -

Overall, a 24-hour sail could eat as much as 260AH. If we were
on an extended passage (where we wouldn't catch up with lighter
usage allowing the wind and solar's refilling the banks after
we'd anchored), we'd have to make reciprocating-engine power if
we didn't have substantial winds and sun to keep up. If the sea
state were appropriate (not dangerous to have it on deck), we
could use the Honda for recharging from time to time, saving the
Perkins' hours (eventual replacement) and fuel costs.

So, that's our electrical picture. "What's wrong with this
picture?"

(I.e., "Where will we get in trouble?", not a request for
opinions on our choices of power using items - however, feel free
to chime in with ideas on power management and sources of
energy-efficient equipment...)

L8R

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Morgan 461 #2
SV Flying Pig KI4MPC
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"You are never given a wish without also being given the power
to make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)