ONE hole per penetration (Pipe, wiring) so it is easy to seal
Climate maps: niwa.co.nz/climate/research-projects/national-and-regional-climate-maps
For best passive heating performance, daytime living areas should face north. Ideal orientation is true north, but orientations of up to 10° west of north and 20° east of north still allow good passive solar gain.
The area of north-facing glass with solar access should range between 15% (for temperate climates) and 25% (for cold climates) of the area of exposed thermal mass in a room.
Fixed horizontal shading, such as eaves, blocks summer sun (which is at a high angle) but allows in winter sun (which is at a lower angle). Fixed shading devices can regulate solar access to north-facing glass throughout the year, without requiring any effort. Correctly designed eaves are the simplest and least expensive shading method for northern elevations.
Permanently shaded glass at the top of the window is a significant source of heat loss. To avoid this, the distance between the top of glazing and underside of eaves or other horizontal projection should be 50% of overhang or 30% of window height, where possible.
The ‘rule of thumb’ for calculating the width of north-facing eaves is shown in the following diagram. This rule applies to all latitudes south of and including 27.5° (Brisbane, Geraldton).
“Most homes need a total of around 900 kilowatt hours (kWh) of electricity per month, or 30 kWh per day. To serve those needs, you’d need a battery bank capable of storing 625 amp-hours at 48 volts.
To keep your set-up as safe as possible we recommend using circuit breakers between on all cable runs”
Look at charging 12/24v battery direct from solar to power lights (24v LED), air, ERV, security, USB (5/12v) powertech.co.nz/products/24-volt-400-ah-battery-kit-narada-rexc-deep-cycle-lead-carbon This saves on inverter capacity.
24v 150w: heliosps.co.nz/product/hps-dc-dc-converters-industrial-waf-150
24v 500w variable output heliosps.co.nz/product/dda-din-rail-mount-non-isolated-dc-dc-converter-250w-500w-tdk-lambda
Install circuit breaker between solar panels and inverter for maintenance safety
https://www.hummingbirdgroup.co.nz/about
Solar Panels
$97.20USD 31 units per pallet = 18kW – Therefore, 2 pallets (2 spares) = 156m2
Panel Efficiency: 22-25% ($12,000NZD)
48 volt
Panel Cooling
Panels working at or below their rated operating temperature have lifespan increased from 30 to 50 years and improved efficiency.
Air movement of 0.5 metres per second (barely enough to move a sheet of paper) creates a cooling effect equivalent to a 3°C drop in temperature. Based on Australia – 25 oC outside creates 90 oC + under panel. So, NZ might have max of 30-50 oC underneath. Therefore, aim for 4m/s air speed.
1/2 = √
Air Velocity: vc = 0.65 [g l dt / (273 + te)]1/2 = 0.61m/s convection speed = 3.6 oC drop without chimney (add 1m/s for chimney of 150-200mm dia, so another 6 oC drop. Total, nearly 10 oC drop.
where:
- vc = velocity in center of airflow (m/s)
- g = acceleration of gravity (9.81 m/s2)
- l = vertical distance from bottom (or top) of the surface (m)
- dt = te – ts= temperature difference between surface and room environment
- ts = surface temperature (oC)
- te = surrounding environment – ambient – temperature (oC)
Sunovate.com.au Use for greenhouse heating or heating thermal mass (Water or sand)
Claimed 300% increase in efficiency (Includes heat recovery for reuse), +50% solar energy conversion efficiency
Flat sheet with tapered risers
Mounting
Cheap tracking system to follow the seasons and arc of the sun. Perhaps Arduino controller and washing machine motor with gearing on a rail track.
Sun Tracking. 20-25% improvement
Easy DIY Solar Tracker:
DIY Solar Tracking System Arduino
Super Cool Phase Change Solar Tracker – No Power Needed
Pursuit Solar: pursuitsolar.com
There is no restriction on size for solar panel arrays in rural zones. Urban has size limits.
Inverters
Multiple inverters cover breakdowns better than a single inverter
Solis 20kW Three Phase Solar Inverter 4G, Dual MPPT With DC Switch $3000 (Need 2) 3P17k-4G
Product Features
- 160-850V MPPT input voltage range- ultra low start-up voltage (180V)
- Over 97.8% Euro efficiency
- Dual MPPT design with precise MPPT algorithm
- IP65 rated for external installation
- RS485 built in /WiFi (optional)/GPRS (optional) interface
- WiFi monitoring available – iphone and android app available
- Multiple protection levels
- Integrated AFCI (DC arc-fault circuit protection)
- 5 years standard warranty 20 years optional upgrade
The Solis WiFi Stick allows you to receive information from your inverter in order to keep you informed about your wind or PV system, everywhere and anytime. $103NZD powerspout.com
Open loop
Inverter must have generator input and Integrated MPPT charge controller, WIFI/ GPRS remote monitoring, Overload, short circuit and deep discharge Protection, Pure Sine Wave.
Normally you don’t want an inverter to be able to discharge a battery faster than 1/5C (20% of total charge per hour). By that logic the battery should be 5 times larger than the inverter. 30kW X 5hr = 150kWh. To convert that kWh into amp- hours just divide the watt hours by the voltage. 150kWh / 48V = 3125 amp-hours. 3125 Ah / 200 = 15.6 Then you can round to 16 batteries.
But this is a problem. If you want a 48-volt system and you only have 200-amp-hours per battery you will wind up with way too many parallel batteries. Batteries in parallel are a nightmare to balance. As a rule of thumb, you should try to never have more than 3 or 4 parallel batteries. Much better to use 6 volt or even 2-volt batteries. You can get 6-volt 800 amp-hour batteries. 8 of these in series is a 48-volt 800 Ah bank. 4 of these banks in parallel would be 3200 Ah.
6 panels (3kW) direct to hot water.
12 panels direct to nightstore type heaters?
Panels to car charger for running 24v lights. Inverter for 12v security and 5v USB supplies
selectsolar.co.uk/prod/1602/solis-40kw-5g-3-phase-quad-mppt-dc#overview $6000 inc. Freight. (Good brand)
SG600 Inverter $72NZD (5k NZD for 60)
NETMS PV Smart Monitoring System $100NZD
Batteries – SLA
Century Yuasa is a good brand. Lives >10 years are possible
36kW/h – so inverter needs 30x 12v batteries 1,000Ah = $4000 x 2 days = $8000
Century Deep Cycle Battery – 27DCMF 96Ah 12v Cold Cranking Amps: 680CCA
Saline-nickel batteries are excellent, but expensive at present (1.5-2x). innov.energy/en/salt-technology
Fuji Bridex’s Sodium Ion Batteries bridex.fujielectric.com/salt-water-battery
Batteries – Lithium
https://arklithium.com/products ARK 512200 48v 200Ah 10.2 kW $5,450USD
SOK Battery | 100Ah 48v | User-Serviceable Rack Mount Battery
$1650USD
10 Year Full Warranty & 20 Year Typical Lifespan
Cells rated for 80% Capacity after 4000 Cycles, 100% DOD @1C Rate
Typical capacity at 80% DOD @.5C Rate is over 7000 Cycles
Lifepo4 48v 200ah Enershare Solar Storage Battery $1300USD ea for 10 units MOQ
GSL 15Years Warranty Wall Mounted Lifepo4 Blade Battery 138 Ah 48v Max.4pcs in parallel(28.0kWh) $2488USD MOQ: 2
NZ Lithium 48V 280AH LiFePo4 Lithium Battery $8500NZD
51.2v nominal voltage
280AH 14KWH energy storage capacity
150a continuous charge/discharge
Touch screen display
Commercial quality aluminum frame and skin 4 lifting eyes
Available with A+ or A- cells
48v (51.2v) 400Ah 20kwh Lifepo4 Battery $10kAUD (Non automotive grade)
Green Bank Solar LiFePO4 15 KWH lithium battery 48V 280AH – WG48280E 6500 cycles $8920AUD 15 year warranty, 29 year lifespan
358v Byd B Box 18kwh Similar Lithium Iron 50Ah 102v or 358v $3900USD MOQ: 2
Build your own solar battery and save thousands David Poz
About $9200USD for 72kWh incl. BMS, excl shipping
Batteries – Redox Flow
https://www.ec21.com/product-details/5KW-10KW-Vanadium-Redox-Flow–9875269.html
Kitsets
14000Wh Solar Kit TOPZS
Contents:
- 9x 270W Solar Panel (USO MPPT)
- 1x Axpert Solar Power Inverter MPX5000 / 48
- 24 x Stationary battery cells TAB TOPZS 442 – 575AH (C100) 442Ah (C10)
Solar Energy Management System
The Sunny Home Manager 2.0 combines all energy flows in your home to create an intelligent system and, upon request, can control them automatically to help you get the most out of your solar power. On the basis of an online weather forecast and your own consumption analysis, the system creates a day-by-day yield forecast. As a result, the Sunny Home Manager 2.0 knows in advance exactly when a lot of solar power will be available and when the right time is to start the washing machine. $1000
