Question

A building with 200,000 ft^{2} of floor area and
lighting power density of 1 W/ft^{2} operates 4,000 hours
per year. Calculate:

1. the electrical demand (kW)

2. the energy use (kWh/yr)

3. the total annual electricity costs ($/yr) for lighting.

Answer #2

Given data,

Floor area (A) = 200000 ft^{2} ,

Power density (p) = 1 W/ft^{2} ,

Annual uses (t) = 4000 hr/year ,

**1. Electrical demand (D)**

D = power density * floor area

= 1 * 200000 Watt

**D = 200 kW**

**2. Energy use per year (E)**

E = Electrical demand * Annual uses

= 200 * 4000

**E = 800000 kWh/yr**

**3. Total Annual Electricity costs (P)**

since no unit cost given for electricity uses, let take A = 0.12 $ per unit of electricity

P = Annual uses of electricity * unit price

= 800000 * 0.12

**P = 96000 $/yr**

answered by: anonymous

Solar cells (the figure) can produce about 40 W of electricity
per square meter of surface area if directly facing the Sun.
(Figure 1) Part A How large an area is required to supply the needs
of a house that requires 22 kWh/day? Assume there are 9 hours of
sunlight per day.
Part B Would this fit on the roof of an average house? Assume a
small house with 1000 ft2 of floor space, and a roof tilted at
30∘.

A warehouse has a total of 35,000SF of floor area. An automatic
sprinkler system is to be installed in the warehouse. The water
supply for fire suppression will be stored in an onsite storage
tank. The hose demand includes both inside and outside locations.
Calculate the water demand and the total water storage needed if:
a) The warehouse is classified as an Ordinary 1 Hazard with a
Density Demand of 0.13 GPM/ft2 and an Overage Factor of 1.2. b) The...

1. Solar cells (the figure) can produce about 40 W of
electricity per square meter of surface area if directly facing the
Sun. How large an area is required to supply the needs of a house
that requires 21 kWh/day? Assume there are 9 hours of sunlight per
day. Express your answer to two significant figures and include the
appropriate units.
2. Energy may be stored by pumping water to a high reservoir
when demand is low and then releasing...

An LED lightbulb, taking in 30 W of power, can produce the same
level of brightness as a conventional lightbulb operating at power
100 W. The lifetime of the energy-efficient bulb is 10,000 h and
its purchase price is $4.00, whereas the conventional bulb has
lifetime 750 h and costs $0.708 per bulb. Determine the total
savings (in dollars) obtained by using one energy-efficient bulb
over its lifetime as opposed to using conventional bulbs over the
same time period. The...

(a) A particular household uses a 2.2-kW heater 3.1 h/day ("on"
time), four 98-W lightbulbs 5.1 h/day, a 3.3-kW electric stove
element for a total of 1.6 h/day, and miscellaneous power amounting
to 2.1 kWh/day. If electricity costs $0.14 per kWh, what will be
their monthly bill (assume 1 month = 30 days)?
dollars
(b) How much coal (which produces 7000 kcal/kg) must be burned by a
35%-efficient power plant to provide the yearly needs of this
household (1 year...

Shine-Ola Premium Bulbs: the Pricing
Decision
Voll Taik, the marketing manager for a new lighting start-up was
very interested in the concept of Value-Based pricing. He was
wondering how he might apply the concept to a situation facing his
company "Shine-Ola".
The new product, "Shine-Ola Premium Bulb", was a LED (Light
Emitting Diode) technology and was dramatically better than
competing lighting solutions available on the market. Competing
solutions included standard incandescent bulbs and compact
fluorescent lighting, (CFL).
Extensive laboratory testing...

The resistivity of copper is 1.68 x 10-8
W-m. The resistance per unit length (R/L) of a
certain copper cable is 1.61 x 10-5W/m.
(a) What is the cross sectional area of the
cable?
(b) The above cable is used to transmit
electricity from a power station to an electrical substation 42.8
km distant. If the voltage at the substation is 2480 V,
what is the required voltage at the power station when the current
running through the cable is 856 A?...

In this exercise we will consider two coal-fired power plants
and a solar thermal plant, in order to compare their power
densities, i.e., their power output vs. the amount of land they
occupy. This method of comparison of diverse forms of renewable and
non-renewable energy systems was pioneered by Vaclav Smil of the
University of Manitoba in Canada. The first coal plant is highly
efficient and is optimally located, next to a mine that supplies
high-quality coal from a thick...

1.Insolation at the top of the atmosphere is about 1367 W/m2.
Earth's diameter is 12,756 km. The total radiation received by our
planet is____Watts
2.Global annual power consumption is about 12.7 x 1012 watts.
Earth's 2017 human population is about 7.5 billion. The power
consumption per person is
----kW.
3.Given that the density of the oceanic crust Perust = 2.99 and
the crustal thickness is about z= 8.4 km, the pressure at the crust
| upper mantle boundary is
-----kPa.

The UAE government is building a pumped storage dam 155 m above the
Hatta dam. Water is pumped up from the Hatta dam during off-peak
hours and released back into the dam (passing hydroelectric
turbines) during peak-hours of electricity use. The total volume of
the elevated storage dam is 800 million gallons (1 gallon is = 3.78
liters and the density of freshwater is 1000kg/m3).
a) Calculate the total stored energy (in Joules) in the elevated
storage dam when it's...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 6 minutes ago

asked 14 minutes ago

asked 28 minutes ago

asked 42 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago