Programming and Learning: eg on Udemy

When you can't get something done, or when you can't understand something, eg when learning on Udemy:

1) Try to find a working example of what you want to do, eg on another web site. Copy and paste and change to your needs. I see Rob doing a lot of copying of existing code from various web sites. This is a good thing in web development.

2) When you are stuck, watch Rob do the work. Then try to do it yourself without watching the video and without referring to what Rob did. Then try again the next day, or when you have time.

3) Sometimes it is difficult to get to certain concepts. I am currently a bit confused between the various syntax requirements in JavaScript, JQuery and PHP, but I guess it will come right with practice. For example string concatenation and $'s at the beginning of variables is slightly confusing.

Keep at it. Don't give up. And remember many of us give ourselves an unnecessary hard time, including me.

Note: Rob is one of the Udemy trainers.

Should local people build South Africa's new power stations?

• Jackie on Facebook:
  
  We should be spending money on training, training, training, so that our own people can do the labour involved in building the infrastructure. If we did that and let them have internships at existing powers stations, etc. they would be ready to do the work themselves. Lure some of our brain drain South Africans back to the country to teach and mentor these trainees and to put proper, affordable and sustainable projects into place to rebuild the country to required levels. Don't have to be a brain surgeon to work out the medium term and more importantly, long term, benefits of this route. How's that Zuma, now can I have a job please!

  Like · 6 hrs
• 

  David Lipschitz 
  My answer:
  
  Hi Jackie. I disagree. What you are describing is already happening out our new power stations and is part of the reason for the incredibly poor quality. New people welding big boilers for the first time at a power station which is 5 years behind schedule.
  
  When you buy a car, you don't need to know how to build it. You need to know how to drive it and if you aren't a mechanic, then you need a mechanic to fix it. You also need the entire supply chain, ie oil, water, petrol, diesel, support, roads, etc.
  
  We desperately need our new power stations for the 2 million peoples' lives that depend on them. 25,000 people spending their entire lives building 2 power stations is great, but what of the other 1,975,000 people who are unemployed because of them?

Permaculture Course in 2010

In the Winter of 2010, June 2010, I did a permaculture course with Robina McCurdy at Jakkalskloof farm near Swellendam.

From my notes: We learnt about Carrying Capacity, Legal Structures, Entry and Exit, Housing Strategy, Financial Constraints, Social Processes, Conflict Resolution, Watched DVDs, went on walks, created a model of the terrain using sand, string for roads and rivers, talked around the camp fire one night, invited the neighbouring farmers round for supper one night. I fed the chickens every day and collected the eggs. Free range, organic, grain fed. Fabulous. Did two 5.30am (rooster woke me up - I had to find out why) meditations with stars so close I could touch them! Saw satellites, shooting stars, aircraft taking off at 6am. Met amazing people. Did Tai Chi on other days. Learnt about "zones" and "seasonal calendars".

All this is important as part of a Community Power Station. If you'd like me to talk about why, please let me know.

Understanding Renewable Energy - Jargon Busting - Training

Please follow Load Sheding Guru on Twitter: https://twitter.com/LoadShedingGuru
Shedding has two D's except on Twitter :)

Please tweet this:

Understand Renewable Energy. Online Training (Webinar) by @LoadShedingGuru . http://loadshedding.guru/webinar-web-seminar/ #LoadShedding

Dramatic Slow Down in Solar Electric (Renewable Energy) Training in South Africa

How to dramatically slow down renewable energy in South Africa. Take a qualification which takes a month in the USA and make it 2.5 years in South Africa!!

These are my official comments:

"2.5 years to do something that can be done in one month in the USA.

"I agree that we need inspectors and perhaps this qualification is more suited to inspectors. However, there are many people who are already installing very competent systems in South Africa and some like mine, which meet the USA NEC Article 690 requirements as far as possible."

http://www.record.org.za/news/item/the-summary-of-qualification-content-pv-technician-for-public-comment#comment-30461

Gecko Rock Solar Electric PV Installation in September 2010

Gecko Rock 8 minute installation and learning video

(as at 19th February 2014, over 2,000 people have watched this video)

(I removed the video in June 2016, and put it back in December 2016)

Gecko Rock (Jonathan Deal) Interview 1 year later

(I removed the video in June 2016, and put it back in December 2016)

Videos filmed and edited by Antony Stone at Big Bang Stunts and Effects

The Team:

Designers: David Lipschitz and Peter Burden
Main Installer: Peter Burden
Metalwork: Designed and installed by Steven Mulder
Videos: Antony Stone

The Client:

Jonathan Deal at Gecko Rock

Specifications:

Overview

• 1.6 kilowatt photovoltaic array with 24 Volt 675 Amp Hour battery bank and 1,200 watt inverter charger with generator backup
• 8 kwh of battery backup
• 8 kwh of average daily solar production from the photovoltaic array

• Location: Gecko Rock, 25 km South South East of Touwsriver, Western Cape, South Africa
• Solar Resource: approximately 5 average peak sun-hours
• Photovoltaic Array Size: 1.62 kW (1,620 watts)
• Nominal Voltage Batteries: 24 Volts
• Nominal Voltage Array: 72 Volts
• Array Voltage at Max Power: 108.6 Volts
• Array DC Current at Max Power: 15 Amps
• Battery Amp Hours: 675 Ah (amp hours) at 20-hour discharge rate. Multiplied by 24 Volts and allowing for a 50% maximum depth of discharge = 8.1 kWh in the batteries for overnight and overcast periods
• Record Low Temperature: unknown; we have allowed for Minus 15 degrees Celsius (during day light (operating) hours)
• Average Low Temperature: 2.2 degrees Celsius in July
• Average High Temperature: 28.6 degrees Celsius in February
• Average Daily Production: 8.1 kWh
• Average Electricity Available after taking account of efficiencies (or inefficiencies): Allow 7% for inverter loss; 20% loss for battery charge/discharge from photovoltaic array; and 2% voltage drop on the cabling: 8.1 kwh * 0.93 & 0.8 * 0.98 = 5.9 kwh per day of usable electricity (daily average over the entire year)

PV System Components:

• 9 Tenesol TE1700 at 24 Volt nominal: 180 Wp STC, 36.2 Vmp, 5 Imp, 44.4 Voc, 5.4 Isc (133.2 Volts open circuit for the array (at zero amps, i.e. first thing in the morning) and 16.2 Amps Short Circuit current for the array)
• Array: 1 “string” of 3 “panels” with 3 “modules” in each panel. Total 9 Modules, 1,620 Watts total
• Array installation: Dual-axis (manual) trackers designed by SolarSells, and enhanced, built and installed by Intricate Steel
• Inverters: 1 x 24 Volt Victron 1200 Watt multi-plus Inverter/Charger allowing 24 Volt DC to 220 Volt AC conversion of electricity and allowing automatic synchronisation of a generator input into the system to supplement the batteries in the case of long cloudy periods
• Solar Charge Controllers: 1 x 80 Amp Outback FM80 MPPT (maximum power point tracking) controller. The FM80 allows array sizes up to 2,000 Watts when charging at 24 Volts. The FM80 allows one to use a higher output voltage PV array with a lower voltage battery, such as charging a 24 VDC battery with a 72 VDC array. This reduces wire size (and cost) and power loss from the PV array to the battery/inverter location and maximises the performance of the PV system
• Batteries: Deep Cycle: 12 x 6 Volt Trojan T105′s in 24 Volt nominal configuration, i.e. 3 banks (in parallel) of 4 batteries (in series) making 24 Volts nominal and 675 Amp Hours capacity. Each 6 volt battery weighs 28 kg making a total battery bank weight of 336 kg. We expect the batteries to last about 8 years with an average discharge of 20% and a maximum discharge of 50%. The batteries have a 2 year free replacement guarantee assuming they are looked after and “watered”, i.e. the battery de-ionised water is checked and filled as required. We can tell how the batteries have been used by looking at the information on the Victron Battery Status Monitor. The Trojan batteries are designed in the USA and assembled in Cape Town
• Generator: 5 kw Honda
• System performance metering: Victron Battery Status Monitor BM 600 for DC performance and battery monitoring; Efergy e2 Electricity Monitor for AC performance and historical AC kwh tracking
• 2 Earth spikes and open earthing cabling allowing all metal work to be earthed. System and Equipment negative grounding. We have used USA NEC Article 690 rules as far as possible as there aren’t standards for PV systems in South Africa yet.

Update:

Subsequent to this original installation, Jonathan upgraded to 3 x 1.6 KW Victron Inverters giving 4.8 KW. He also upgraded his battery bank to 1125 AH at 24 Volts. Interestingly he discovered that he doesn't need to cook with gas anymore and that he can power his cooking with his microwave / convection oven. This provided an unexpected saving with the system.