Step-by-step design trade-offs across the workflow — pick the better choice for each user goal and see why with real numbers.
A fixed three-question set for newsletters and sharing — the questions stay the same all month.
Three design trade-offs this month — system size, panel orientation, and solar-only vs battery. Same scenarios all month for each hemisphere (pick northern or southern above the questions).
3 questions
Start monthly quiz →Practice one design guide step at a time — questions filtered to that part of the workflow.
Step 1 · Goals and system type
Solar-only vs adding a battery — when hybrid pays off on 25-year savings, and when a larger solar-only array beats a smaller hybrid on annual bills (and when low export rates flip that result).
4 questions
Start quiz →Step 2 · Site assessment
Shading trade-offs — does removing a tree pay off on payback and long-term savings?
2 questions
Start quiz →Step 4 · System size (kW)
Payback and 25-year net savings — how array size and upfront cost trade off when the array is too small, about right, or oversized.
4 questions
Start quiz →Step 5 · Choosing and placing panels
Orientation, tilt, flat-roof mounting, and load shape — generation, savings, and self-sufficiency trade-offs on the roof.
8 questions
Start quiz →Step 6 · Choosing an inverter
String vs microinverter — shade recovery and micro premium at 25 years, then mixed-orientation capacity at 25 years and payback.
4 questions
Start quiz →Step 8 · Battery storage
Solar-only vs adding a battery on the sized design, whether surplus solar can justify a larger pack, then small vs large kWh on savings and self-sufficiency.
4 questions
Start quiz →Tariffs are illustrative only, in USD, not local currency.