Self-tutoring about electricity and energy: the tutor mentions some units new to him. At an electricity generation plant, MWt means “megawatts thermal.” It measures the energy input. MWe means “megawatts electrical.” It’s the output. When burning fossil fuel such as …
Energy: electricity generation units: MWe vs MWt Read more »
Tutoring chemistry, the distinction between cell and battery is noted. In electrochemistry, a cell is a single unit of electrical energy production. A cell comprises an anode and cathode, plus the ingredients and the environment needed for the chemical reaction …
The tutor defines two terms relating to auto batteries. The reserve capacity (RC) of a car battery is given in minutes. It’s the duration the battery can discharge 25A at ≥ 10.5V. Ampere hours (Ah), on the other hand, is …
Auto batteries: reserve capacity vs Ah (Amp*hrs) Read more »
The tutor examines the idea that internal combustion engines are more efficient in cold weather. An upper limit for efficiency of an internal combustion engine is eff = (Tcombust – Tsurrounding)/Tcombust where Tcombust is the temp of the combustion cylinder …
Physical chemistry: efficiency of internal combustion engine in hot vs cold weather Read more »
The tutor investigates higher household usage over last year. For Nov11-Jan11, our daily household usage this year was 6kWh above last year. My wife points to the new electric fireplace downstairs as the culprit. More specifically, she means that it’s …
The tutor discusses a surprising event last night. Lately, our electricity has been blinking sometimes. My wife said we should call someone; I said I didn’t expect it was from our own wiring. Therefore, I reasoned, other people would likely …
The tutor explores a common topic among families. Lately, I’ve been driving the kids to their activities and my wife to and from work. While there’s rarely been a dull moment, I’ve arrived at the topic of fuel consumption and …
The tutor offers an estimate about the price of going solar. In an earlier post , I reported my research findings of possibly 22W per $100 for a residential solar application. Here in BC, according to BC Hydro, the typical …
The tutor takes a detour from his solar energy series to explain kiloWatt*hour. A kiloWatt*hour means 1 kiloWatt multiplied by 1 hour. (The asterisk means “times.”) A Watt is energy used per second – aka, power. The unit is named …
Residential electricity: what is a kiloWatt*hour (kWh)? Read more »
The tutor continues from his last post about the value of solar energy dollars. In my last post I discussed the Wattage one might expect from solar energy for $100. Based on a graph from Scientific American, the equation for …