Lifestyle
EV Basics – What’s a kilowatt hour?
So what’s a kilowatt hour or shall we ask Watts a Kilowatt hour?
As more car buyers take the plunge into owning an electric vehicle (EV), it’s important to educate on the EV specific units of measure which differ greatly than your traditional gas burning vehicle. What is a kilowatt hour? How does it differ from a kilowatt? And why does this even matter?
Background
First, let me preface everything by saying that much of what I’m about to write is based on US specific units of measure since that’s what I’m familiar with. For instance, miles vs km and US dollars versus Euros. I’m also over simplifying and breaking things down to basic laymen terms so please cut me some slack if you already know all this!
If you receive a utility bill for your residence then you should probably be somewhat familiar with, or have heard of, a kilowatt (kW) and kilowatt hours (kWh) since that’s what electricity bills are measured on. Your EV is no different and uses these same units of measure although it’s probably something you haven’t paid much attention to in the past.
kW and kWh Units
Depending on the EV display you may see watt hours (Wh) or kilowatt hours (kWh) in some places and watts (W) and kilowatts (kW) in others. The kilo or k is a standard prefix meaning a thousand. So 1 kWh is 1,000 Wh. If you own your EV long enough you may just get to the next level, megawatt hour (MWh) which would be one million Wh!
Now for the fundamental definitions:
kW is a measurement of power and kWh is a measurement of energy.
Energy is the amount of work that can be performed. kWh, calories, joules are all units of energy. A slice of pizza has 285 calories which is 0.33 Wh of energy that can be derived from that substance. Energy can be converted and change in form. For instance we can convert that slice of pizza to heat by setting it on fire. The fuel is the pizza, but don’t try converting it in your EV!
Power is the rate at which energy is generated or used. kW is a unit of power. When you accelerate in your EV you’re using power and when you decelerate with regenerative braking you’re generating power. The Model S dedicates half the speedometer display to the unit of power on the right side. There you can see how many kW you are using (indicator is orange) or generating (indicator is green) at any instance in time. It’s great to be able to see this however you can’t easily convert this into a cost. In order to do that, you’ll need to measure it over time and convert it into a unit of energy.
Power is similar to your speed. 50mph is your speed, but you have to maintain that for an hour to travel 50 miles. Similarly, 40kW is how much power you’re using and you’ll have to maintain that consumption for one hour to use 40kWh. If you spend half that hour at 40kW and the other half at 20kW you’ll end up consuming 30kWh. Power usage is constantly changing and will depend on driving habit as well as usage of onboard amenities such as your seat heaters or A/C unit.
A 100W incandescent light bulb used over 1 hour will consume 100Wh of energy. If you use that 100W bulb for 8 hours every day, it will consume 800W or 0.8 kWh per day. After 30 days, it will have consumed 0.8kWh x 30 = 24 kWh. After 365 days it will have consumed 292 kWh. Measuring your EV is done in a similar fashion but keep in mind that an EV can both use and generate power (regenerative braking) over periods of time. The difference or net power used (used – generated) is what you see reported on your EV display.
Units for Charging
Charging your EV you transfers energy back into your battery so you’re effectively storing kWh for later use. EVs report charging in different ways but the most common is to report by kW and kWh added. So a charge rate of 6 kW is storing 6kWh for every hour of charge. If you’re charging at 6kWh and charge for 2 hours you’ll have an extra 12kWh added at the end of your charge.
When it comes to driving, we’re trained to think in terms of miles, but not all miles travelled are the same when it comes to energy usage since there are variations in terrain and elevations. Weather also plays a factor for each mile travelled. A kWh stored, on the other hand, is always the same. The main difference is how you use that kWh.
The Model S offers the option to display charge rate by kW and kWh or by miles. Not surprisingly most Tesla owners choose to display charge rate in terms of miles. However it’s important to note that there’s a huge assumption being made about how many miles you can drive on a Wh and that assumption needs to account for charging efficiency. Tesla uses their proprietary algorithm to compute this value.
On Tesla’s online calculator they assume 300Wh/mile average use and a 90% charging efficiency. My own measurements show the average Wh/mile usage to be a bit higher (306 lifetime average) and the charging efficiency to be slightly less (81% last month).
What about Volts vs Amps?
Now you may be wondering how all this relates to volts and amps. This gets us back to the basics. One can calculate watts by multiplying volts with amps. W = V x A. So if you’re at a public charger and it’s charging at 199V and 30A (reference picture above), you’re essentially charging at 199V x 30A = 5,970W or about 6kW. This equates to 6kWh added after an hour of charging, but as we all know this is based on an ideal world where it charges at 100% efficiency with no loss. At 199V and 30A, the Model S is reporting this as a rate of 16 mi/hr.
Lets check that math:
5,970W/300Wh/mile standard assumption = theoretical 20 miles/hr charge rate. But that doesn’t account for charging efficiency. The Model S is reporting 16 mi/hr so its assuming an 80% charging efficiency (16/20) under these conditions.
Cost
Utility bills price per kWh. Your electric company may break it down by distribution vs generation, time of use, etc. and then associate a different cost per kWh on each pricing tier. It seems complex but you can simplify this.
To figure out your total cost per kWh just take your total amount of the bill and divide it by your total energy usage for the same period. That may include the various service fees, taxes, etc. but in the end you’re paying the electric company that total amount for those kWh regardless of what it’s derived from. Knowing this will help you calculate the costs for your road trips based on the kWh used.
Summary
Lifestyle
Tesla hit by Iranian missile debris in Israel
A Tesla in Israel absorbed a direct hit from missile debris, and the glassroof held.
On March 30, 2026, Lara Shusterman was in Netanya, Israel when Iranian ballistic missiles triggered air raid sirens across the city. While she remained in safety, her 2024 Tesla Model Y did not escape untouched. A heavy piece of missile debris struck the car’s massive glass roof, leaving a deep crater but without shattering. In a Facebook post to the Tesla Israel community the following morning, Shusterman described what happened: “The glass did not shatter into dangerous shards. She stopped the damage and pushed the metal part to the ground.” She closed by thanking Elon Musk and the Tesla team for building what she called “security and a sense of trust even in extreme situations.”
Netanya is a coastal city in central Israel, roughly 18 miles north of Tel Aviv and has been among the areas most frequently struck during Iran’s ongoing missile campaign, following coordinated U.S. and Israeli strikes on Iranian military infrastructure. Falling shrapnel from intercepted missiles is a common occurrence.
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- Tesla Model Y glass roof shattered from a piece of falling Iranian missile debris
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- A piece of Iranian missile debris that struck Lara Shusterman’s Tesla Model Y in Netanya, Israel on March 30, 2026, after being intercepted by Israeli air defenses.
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- Tesla Model Y glass roof shattered from a piece of falling Iranian missile debris
Source: Tesla Israel Facebook Group
The incident is a testament to Tesla’s structural engineering. Tesla’s glass roof is designed to support over four times the vehicle’s own weight. That strength has shown up in real-world accidents too. In 2021, a Model Y in California was struck by a falling tree during a storm, with the glass roof holding firm and the cabin remaining intact. In another widely reported incident, a Tesla Model Y plunged 250 feet off the cliff at Devil’s Slide in California in January 2023, with all four occupants, including two young children, surviving.
Disturbing details about Tesla’s 250-foot cliff drop emerge amid initial investigation
Tesla officially launched sales in Israel in early 2021 and captured over 60 percent of Israel’s EV market in the first year. The brand’s foothold in Israel remains significant. Tens of thousands of Teslas are now on Israeli roads, making incidents like Shusterman’s easy to corroborate. On the same week her Model Y took the hit, the U.S. Space Force awarded SpaceX a $178.5 million contract to launch missile tracking satellites, a separate but fitting reminder of how intertwined the Musk ecosystem has become with the realities of modern conflict.
Elon Musk
NASA sends humans to the Moon for the first time since 1972 – Here’s what’s next
NASA’s Artemis II launched four astronauts toward the Moon on the first crewed lunar mission since 1972.
NASA’s Space Launch System rocket launches carrying the Orion spacecraft with NASA astronauts Reid Wiseman, commander; Victor Glover, pilot; Christina Koch, mission specialist; and CSA (Canadian Space Agency) astronaut Jeremy Hansen, mission specialist on NASA’s Artemis II mission, Wednesday, April 1, 2026, from Operations and Support Building II at NASA’s Kennedy Space Center in Florida. NASA’s Artemis II mission will take Wiseman, Glover, Koch, and Hansen on a 10-day journey around the Moon and back aboard SLS rocket and Orion spacecraft launched at 6:35pm EDT from Launch Complex 39B. (NASA/Bill Ingalls)
NASA launched four astronauts toward the Moon on April 1, 2026, marking the first crewed lunar mission since Apollo 17 in December 1972. The Artemis II mission lifted off from Kennedy Space Center aboard the Space Launch System rocket at 6:35 p.m. EDT, sending commander Reid Wiseman, pilot Victor Glover, mission specialist Christina Koch, and Canadian astronaut Jeremy Hansen on a 10-day journey around the far side of the Moon and back.
The mission does not include a lunar landing. It is a test flight designed to validate the Orion spacecraft’s life support systems, navigation, and communications in deep space with a crew aboard for the first time. If the crew reaches the planned distance of 252,000 miles from Earth, they will set a new record for the farthest any human has ever traveled, surpassing even the Apollo 13 distance record.
As Teslarati reported, SpaceX holds a central role in what comes next. The Starship Human Landing System is under contract to carry astronauts to the lunar surface for Artemis IV, now targeting 2028, after NASA restructured its mission sequence due to delays in Starship’s orbital refueling demonstration. Before any Moon landing happens, SpaceX must prove it can transfer propellant between two Starships in orbit, something no rocket program has done at this scale.
The last time humans left Earth’s orbit was 53 years ago. Gene Cernan and Harrison Schmitt of Apollo 17 were the final people to walk on the Moon, a record that stands to this day. Elon Musk has long argued that returning is not optional. “It’s been now almost half a century since humans were last on the Moon,” Musk said. “That’s too long, we need to get back there and have a permanent base on the Moon.”
The Artemis program involves 60 countries signed onto the Artemis Accords, and this mission sets several firsts beyond distance. Glover becomes the first person of color to travel beyond low Earth orbit, Koch the first woman, and Hansen the first non-American astronaut to reach the Moon’s vicinity. According to NASA’s live mission updates, the spacecraft’s solar arrays deployed successfully after liftoff and the crew completed a proximity operations demonstration within the first hours of flight.
Artemis II is step one. The Moon landing and the permanent lunar base come later. But after more than five decades, humans are heading back.
Elon Musk
Tesla Optimus Gen 3 is coming to the Tesla Diner with new ambitions
Tesla’s Optimus robot left the Hollywood Diner within months of opening. Now Musk is planning its return with a bigger role and a major Gen 3 upgrade underway.
![Tesla Optimus Gen 3 [Credit: Tesla]](https://www.teslarati.com/wp-content/uploads/2026/03/tesla-optimus-gen3-diner.jpg)
Tesla’s Optimus robot was one of the most talked-about features when the Tesla Diner opened on Santa Monica Boulevard in Hollywood on July 21, 2025. Dubbed “Poptimus” by Tesla fans, the Gen 2 robot stood upstairs at the retro-futuristic, drive-in theater and Tesla Supercharging station, scooping popcorn into bags and handing them to guests with a wave.
The diner itself had been years in the making. Elon Musk first floated the idea in 2018 with a tweet about building an “old-school drive-in, roller skates & rock restaurant” at a Hollywood Supercharger. What eventually opened was a unique two-story neon-lit space, with 80 EV charging stalls, and Optimus serving as a live demonstration of where Tesla’s ambitions were headed.
If our retro-futuristic diner turns out well, which I think it will, @Tesla will establish these in major cities around the world, as well as at Supercharger sites on long distance routes.
An island of good food, good vibes & entertainment, all while Supercharging! https://t.co/zmbv6GfqKf
— Elon Musk (@elonmusk) July 21, 2025
But Optimus did not stay long, and was gone by December 2025.
Now, the robot is set to return with a more demanding job. Musk has ambitions for Optimus to take on a food runner role in 2026, delivering meals directly to cars at the Supercharger stalls. While the latest Gen 3 Optimus is likely to initially take on its previous popcorn-serving role, it wouldn’t be out of the question for Optimus to see a quick promotion. With improved hand dexterity that features 50 total actuators and 22 degrees of freedom per hand, and significantly more powerful processing through Tesla’s latest AI5 chip that includes Grok-powered voice interaction, Musk described Optimus at the Abundance Summit on March 12, 2026, as “by far the most advanced robot in the world, Nothing’s even close.”
Back to work
See you at Tesla Diner tomorrow pic.twitter.com/H3tTajrUbu
— Tesla Optimus (@Tesla_Optimus) March 30, 2026
That confidence is backed by a major manufacturing shift. At the Q4 2025 earnings call in January, Musk announced Tesla would discontinue the Model S and Model X and convert those Fremont production lines to build Optimus. “It’s time to basically bring the Model S and X programs to an end,” he said, calling for a pivot that reflects where the Tesla’s future lies.
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