David Dunnett

Working to replace fossil fuels. Battery storage, microgrids, home electrification. Real-time power control and mathematics.

Personal account, own opinions.

[David Dunnett @d_dnntt]

@duncancampbell Complaining about excess capacity is such a weird abstract complaint. If system LCOE is good and it gets you electricity, who cares? I generally expect something on the order of 2x peak load for PV/wind cap, 1X peak load for BESS, backup gensets covering about 1.5x peak load.

[David Dunnett @d_dnntt]

@40PercentGerman Pour over ftw

[David Dunnett @d_dnntt]

@christaggart Love the station in the Glebe. Downtown Kingston also has a great old transformer station.

[David Dunnett @d_dnntt]

@duncancampbell @drvolts Wait looking again - is the genset 800kW rated and going full power when it goes on? And looks like a pretty steady 200kW demand? I'm surprised by the over dimensioning. Only one backup genset?

[David Dunnett @d_dnntt]

@duncancampbell @drvolts Back up gensets will be with us along time I think. Ideally with biofuels and less than daily use though. You want to get that genset on during high demand though if you can, and save the battery for longer discharge during low demand.

[David Dunnett @d_dnntt]

@drvolts @duncancampbell EWT in the UK do this, and I've seen other attempting. It's not widespread but it exists. Small turbines obvs. This kind of industrial microgrid for limited grid cap is going to be the new normal imo.

[David Dunnett @d_dnntt]

@HarrisBerton No one wants thermal runaway in their hand....

[David Dunnett @d_dnntt]

If you have a USB-C charge port getting clogged with lint I can highly recommend snipping a guitar pick into a skinny sharp point to clean it!

[David Dunnett @d_dnntt]

@the_transit_guy Its just the world's worst roundabout isn't it

[The.Ink, from Anand Giridharadas @AnandWrites]

For decades, Democrats ceded the idea of freedom to the right.

Can Joe Biden reconquer the freedom frame tomorrow night?

In The Ink today: https://t.co/s0q0qNiecP

[Horizon Ottawa @HorizonOttawa]

It's 15 degrees and a thunderstorm...in February.

The climate crisis is here and #ottcity council needs to take it seriously.

Next Tuesday, we'll be pushing councillors to ban fossil fuel advertising.

Find below how to contact members of the committee dealing with this issue:

[Sam Hersh @SamHersh01]

A thunderstorm in February is not normal.

We can't allow oil and gas to continue profiting off the climate crisis.

If you live in #Ottawa find out below how to contact your #ottcity councillor and demand they support a ban on fossil fuel advertising in local facilities.

[Rideau Canal Skateway @NCC_Skateway]

It's the news we've been waiting for!

Tomorrow, Sunday Feb 18, a section of the #RideauCanal Skateway will open:
📍 between Pretoria and Bank
⌚ at 12 noon
🧊 conditions will be variable

See you on the ice! 🎉🧊🥶 #ottnews

[David Dunnett @d_dnntt]

@duncancampbell Control can get through, especially with certification. We see that in UK, German and Australian markets.

[David Dunnett @d_dnntt]

@duncancampbell Hmm. You're looking for a digital input that confirms the grif breaker is open in order to allow discharging? You can definitely set up a weak-grid application that only connects to the grid if the battery is low (or full I suppose). But this actually reduces your flexibility.

[Laurel Collins @Laurel_BC]

Today marks one year since the public was made aware of the toxic tailings pond leak from Imperial Oil’s Kearl site, which was revealed due to another spill of 5.3 million L of industrial waste spilling into the environment.

1/5

[David Dunnett @d_dnntt]

@the_transit_guy Also important is that the train drop you off in a central location where it is then possible to get around easily without a car. Huge factor in the success of train connections.

[David Dunnett @d_dnntt]

@HarrisBerton @SamHamels @Ember421 That's pretty good. I 100% agree that zone control is key both for comfort and efficiency.