Energy savings long cited as an advantage in the development and use of subsurface mined space have often been speculative. Unbiased data must be that which is accrued by using metered measurement of all energy consumption for those surface and subsurface facilities which are of comparable size, structure, and similar daily functions. It is also necessary to use a common denominator such as the quantity of B.T.U.s consumed rather than cost as rates may vary from one user to another.
This study attempts to objectively analyze energy use effectiveness of comparable surface and subsurface facilities accounting for all variables. Data was gathered from 13 selected facilities in the Kansas City area, seven of which were located underground and six were located above grade. Of the six which were above grade, two were in the service category, two in the warehousing category and two were in manufacturing. Of the seven which were underground, two were in the service category, two were in the warehousing category and. three were in manufacturing. Savings of 47 to 70 percent were found and a general conclusion explaining these results is offered.
The use of mined out space in limestone has become for several an acceptable and desirable form of land use. Greater Kansas City, because of its favorable geology and prominent bluff topography has led the United States in its use of the room and pillar method of limestone mining and in the subsequent conversion of these rooms from mined space to industrial and commercial space. Some fifteen sites in Greater Kansas City are currently using over 2,000,000 square meters of underground mined space to serve over 200 industries employing nearly 3,000 persons from 15–65 meters below the surface. Additional mined space is being developed constantly and its uses include almost any use commonly thought limited to a surface location only. Energy savings have long been cited as an advantage in using the subsurface as compared to the surface.
These claims are used in marketing underground space to prospective tenants. Energy savings has also been cited as one of the unique characteristics of underground development. There is seldom a reference to underground development and use that does not in some way cite energy conservation as an attribute. The amount of energy savings one may gain through a subsurface location has been quoted as low as 15% to as high as 90%. These figures have too often been produced by less than hard core metered data. Those who have speculated a savings figure have been noble in their intention but often failed to accurately account for intervening variables. The size of an operation is one intervening variable which may influence its efficiency. The general structure of an operation can also render it a good or a poor example of wise energy use. The daily use of a facility can range from fanning the doors every few minutes to seldom opening them.